Hi Michelle, and thanks for sharing your work here on Scribophile!  Almost nobody is naturally good at writing, despite myths to the contrary.  You have a good start, and the most important things: A story, and the desire to write it.  Now all you have to do is work at it until you're blue in the face!

Here are a few general suggestions for areas I think you should focus on, and then I'll go into this story in detail and show you some examples.

* Your dialogue is very stilted and unnatural.  Try saying any of it out loud and you'll see what I mean.  Run a google search for "Writing believable dialogue" (or without the ue if you're American) and read through a few dozen of the pages that finds.  "Shut up!" he explained, by William Noble, is an entertaining look at this topic as well.

* Spell-check and grammar check!  It only takes a few minutes, and is fairly easy.  If you're not good at spelling and grammar, find a friend who is and convince them to help you out.  There's no excuse for things like "a secret gole"!  Always proof-read something after you've finished writing it.

* Don't try to put too much information into any one sentence.  I'm guilty of this myself, so I can relate.  Short concise sentences are usually a lot easier for people to absorb, though.  If you have to, you can always add in additional sentences later.

* Watch for tense and subject disagreement.  Don't start a sentence in the present and then move the rest of the verbs into the past, or vice-versa.  Don't switch between first-person and third-person views.  Pick one and stick with it.

* Watch for contradictory prose.  If you say something is X, make sure you're not saying it's Y a few paragraphs later.  It can sometimes help if you have a "cheat sheet" sort of thing with all the important plot points written out.

* Don't be too descriptive.  Throwing in adverbs willy-nilly into every place they'll fit is really distracting.  The name for this among writers is "Purple prose".  If you use an adverb, make sure it's absolutely essential to the story.  If you could do without it, or make it clear to the reader in some other way what's going on, do that instead.

So now on to the critique of this story in particular:

Swiftly moving around the dark room, John paused and scanned his room full of happy childhood memories then quietly slipped out the first floor window.

This is an example of "too much in one sentence" and a minor one of "contradictory prose".  He's swiftly moving, but he's also pausing?

Two years later...

This isn't a very good transition.  It might be more effective to separate the first paragraph really noticeably (with a visible line or some other technique) and then just mention later on it's been two years.  At one point Sarah mentions his disappearance, so that would be a good time to throw this in.

Sarah stared out the dusty window, eagerly looking for her parents among the 1,999 people walking home from the factory.

At first 1,999 stuck out like a sore thumb.  It does make sense, though.  This sentence is actually a good one.  If you can make the rest of the story more like this stylilstically you'll be on the right path!  What are the chances that all of the rest of the town's population works at the factory and that their house is in sight of the factory though?  There might be a better way to segue into the 2,000 population thing.

Squinting her green eyes at all the sooty faces, she finally spots the two short and plump familiar forms.

Without the capital Squinting and the comma after faces, this reads like a sentence fragment.  This is where you start to get a bit too descriptive, as well.  Green eyes is okay if it's important, sooty faces and "short and plump familiar forms" is too much.

Neither of which had anything in their hands.

This is a sentence fragment.  I also don't know what purpose it's supposed to serve.  Is it somehow significant that there's nothing in their hands?  If it isn't, don't mention it.

Taking a disappointed breath sarah walked over the unfinished wood floor to open the door for them.

I think I missed this sentence the first time, so I guess it is significant.  "A disappointed breath" is a great example of where you could show not tell.  Show how she's disappointed with her dialogue or by showing her doing something that makes the reader go "Oh, she's disappointed."

"Thank-you Sarah" her father said absently,

More extra adverbials.  "Thank you" doesn't use a hyphen.

"Laura, Honey, maybe they are just trying to make sure that we are not hiding John.  After-all our town has reached the two-thousand limit."

Really unbelievable dialogue.  Read it out loud and see if it sounds like something anybody would say.  "After-all" doesn't have a hyphen there.

Furrowing his brows and giving a heavy sigh he sat down in one of the three rough, wooden, kitchen chairs then looked up at sarah's mother who had moved to stand in front of him with folded arms.

Too much action in one sentence.  If he's sitting at a "kitchen chair" it gives the idea that he's also at a "kitchen table", which makes it hard for her to stand in front of him.

"Furrowing his brows, he sat in one of the three rough wooden chairs.  Sarah's mother stood next to him with arms folded."

That reads a lot more cleanly.

Pacing the small one window room she continued in a steadily frenzied voice.

Something that's frenzied isn't steady.  "steadily more frenzied"? 

  Slumping into the chair beside him Laura continued, "it was just coincidence that John went missing three days before Jahan Valsman was appointed World Leader and... destroyed everthing."

At first (for some reason) I thought it was Sarah saying this instead.  The dialogue isn't too bad here.  Although you're missing a y in everything.

Sarah grabbed the two day old bread and the hot corn from on top the  wood stove and placed them on the wooden table then sat in the last chair.

Two day old bread is on top of the stove?  You probably don't need to say that she sat down, either.

Her excitement at having fresh bread now dead, turned into a sickening black pit in her stomach.

This is a sentence fragment as it stands.  Try:

Her excitement at having fresh bread now dead, turned into a sickening black pit in her stomach.

although the last part still doesn't make a lot of sense.

Scorching hot pain from the corn fell on Sarah's lap caused by the loud baning on the door.

Consider a moment:  She was about to put this corn in her mouth!  It shouldn't be so hot she can't even touch it.  The sentence is also rather muddled.  Try rewriting it so that the banging on the door is first:

A loud bang on the door startled Sarah, and she dropped the hot corn into her lap.

Mother fluttered around trying to clean up behind them.

This is kind of a strange reaction.  If the FBI come to your house and start ransacking it to look for something, are you going to go around after them and clean?  It also doesn't match with what she says later.

"There's nobody here!" her mother yelled, panicky

Likewise, the father's reaction and dialogue don't match up:

Father stayed in his seat his face looking redder and redder

.........

"Let them search the house." father said.

If you go through the rest of this story and try making similar changes to the ones I suggest above, this will be a whole lot more solid.  I do think you have an interesting story here!  I'd like to see what happens next, so keep on writing!  Just make sure you proof-read, please!

Looking forward to seeing your second draft of this.

Definitely a big improvement!  Now work on some of those pesky sentences-that-need-commas in them

 A good rewrite, Michelle.  Stewart's critique was right on.  It's a good story and I'd like to read more of it, but first, there are a few little things that need attention.  

"Thank-you Sarah" her father said,

That pesky hyphen is still there and when you take it out, put a comma after the "you".

"Laura, Honey, maybe, it’s just a routine check. I mean, this is the first time our town has reached the population limit. The SIB’s probably do this to every town. “  Sighing he sat down in one of the wooden, kitchen chairs.

Here we go with the commas  Take out the one after "maybe".  Put it after "Sighing".  Take it out after "wooden".  

Mother grabbed a broom to sweep away at the incessant dust, shaking her head she countered,

"The S.I.B’s are not called the Select Imperial Battalion for nothing.  They work for Jahan Valsman not the Town Chief. If the S.I.B.'s were here to hunt down renegades...,"

"There are lots of families missing people. People they know didn’t sign Valsman’s contract" father finished

You need a period after "dust", a comma after "Valsman", and a period at the end of the

sentence.

  Slumping into a chair Mother continued, "It was just coincidence that John went missing three days before Jahan Valsman was appointed World Leader and... destroyed everything."

Here's a really good paragraph.  Sets up John's disappearance and tells us about the World Leader.

While listening to the conversation, Sarah grabbed the old bread and the corn from on top the wood stove to put on the table.  Her excitement at having fresh bread, turned into a forbidding nervousness, a family had already been discovered hiding a relative underneath floor boards and it had only been a week since the town had reached the 2,000 mark.

I still don't get why the bread's on top of the stove cooking with the corn.  But the next sentence needs a lot of work.  I think you mean that she had been excited at the thought of having fresh bread.  This emotion turned into nervousness, but forbidding?  She knows John's not hiding in the house.  What you need is some transition to reveal the information about the family with the hidden relative.  Good also to reinforce the established population limit.

With parent’s only half-way out of their seats and Sarah frantically wiping the corn off her lap, the door flung open, filling with the distinct attire of the SIB’s. Who began barraging through everything within reach.

No apostrophe in parents, no hyphen in halfway.  I think you mean "barging" (to move about clumsily), rather than "barraging" (directing artillery fire).  Something like:  "When the door was flung open, her parents were halfway out of their seats as Sarah frantically wiped the corn off her lap.  The SIBs, in their distinct attire, entered and began barging through everything within reach."

tearing up floorboards, flipping the bed, and tearing off roof shingles. 

Roof shingles are outside; these guys are inside.

Leaning around some of the SIB’s Sarah saw the leader hold up a small single battery flashlight, her stomach crashed to the floor while her heart jumped through her chest.

First, this is two sentences, with a period after "flashlight".  Second, the vision of her stomach and her heart heading in different directions is not what you want to evoke.  You can say "seemed" or "she felt as if...".

There are a few ending periods missing from the next sentences.

"I'm not leaving to the reformation school just because of a flashlight, that isn’t even ours." Stated father

"going to" and the period should be a comma, i.e., "I'm not going to the reformation school just because of a flashlight that isn't even ours," stated father.

Being a non-pervasive person,

This is probably the wrong word.  Do you mean "passive"?  

There is no indication of Sarah's age.  Apparently she was the only person in the town not employed in the factory.  Why?  Is she too young, or incapacitated in some way?  

Throughout, you say "SIB's" -- the apostrophe isn't necessary.  

Writing is a lot of work; even more after the first draft.  Read, reread, and read again, but never get discouraged.  You have a good idea, and I'm looking forward to reading more.  I want to know where John is, and how he gets in touch with his family, especially his sister.  Go!