The Start Of it All(part 1)

This story starts with a young,average,American girl named Tiana. Tiana when she was little had the wildest imagination like every other toddler in town,her little world was perfect. She had the bestest of friends in elementry school and would never forget them and never did,but because of her parents jobs sadly Tiana had to move,and from that point on it was all over for her...the nightmare truly began. Tiana Anderson was no longer the little girl from across town..she had to go to a different school and meet different people. Those people were not the nicest people in town,the kids she met were raised by beastly parents and never once could she do anything about it,by the time Tiana grew older in the 8th grade she was she was still as usual taunted and teased. No boys liked Tiana,she had very few friends but the ones who were her friends were the closest people to her heart besides her family. Things were about to change for our creative,innocent,loyal and smart Tiana,God had a plan for her. By time highschool started she had gotten a boyfriend.."too bad he turned to be a lying,cheating snake" said Tiana,"dont worry about it sweetheart it wasnt meant to be...besides you can do wayy better" said her bestfriend Lauren,Lauren was the only girl who accepted Tiana before and after she had a huge weight gain and loss.Eventually Tiana gained more and more friends, yet she was still heartbroken in the 10th grade and 11th. So there it is Tiana a senior and still no one to call her own since her on and off dating in the 9th grade with some jerk who took her virginity. She didnt know what was wrong,she was told she looked good alot and she had the perfect personality,but she just guessed that all the guys didnt want a relationship and the ones that did already had girlfriends. But no one knew,no not even us,knew that she had a deeper darker hidden secret,one too complicated for one mind to understand...(to be continued)

Hello!
Let me just say that my first impression of this was "Oh my...ginormous paragraph." You definitely need to divide this up some to make it easier on the readers. My eyes jumped around a bit and I kept having to find my place ._.
One thing that I think can be improved upon is the fact that so much of this is just summarizing. Here is where "showing, not telling" comes into play. Maybe instead of saying some of these things outright, put in a bit more dialogue, or describe a specific scene to give an example.
Another thing that bothers me somewhat is your tone. You really need to establish the voice that the narration is in. Your tone seems to change a lot from the beginning to the end.

This story starts with a young,average,American girl named Tiana.

In my opinion, one of the most important things about a story is a real attention-getting opening. This sentence doesn't really do much for grabbing the reader's attention and think "hey, I wonder what's happening. I should read more and find out."
Another thing that is incredibly important is developing your character. Through reading this I know very little about how Tiana thinks and how she would react to certain situations. This is a difficult thing to master, and it definitely takes a lot of practice to get there. One way of showing a character's personality is dialogue. The way a person talks can say a lot about their character. If it's an omniscient third-person point of view you could include some of your characters' thoughts. Again, this goes along with the showing not telling idea. I would also suggest describing Tiana a bit. It's important to know at least a little what your main character looks like.
I can see quite a few grammatical errors that need cleaned up. You have several run-on sentences that make it sound a little rambling, and you are missing several spaces. Good rough draft, but it needs some work.
Hope this helped! Let me know if you have any questions.
~Devan

I'll do the grammar/small nit picking stuff for you:
-- Commas; please put spaces after the commas. So rather than "young,average" it should be "young, average"
-- Run on sentences; don't be afraid to throw in periods.
-- Childish English; you use words such as bestest, which is ok if you were writing a children's story. But if you're writing anything else, refrain from using such words.
-- Tone; you write as if you are talking to the reader. If that is your style, I suggest writing a "fantasy diary" or something along those lines. Generally, you want to tell a story and not talk to the reader like they're your best friend.
-- Plot; you leave a lot of things out that leave the reader hanging. The ending, admittedly, had me curious. But throughout the story, we don't know a lot of things such as/you throw stuff at us that you never mentioned before: the weight gain and loss, her friends, her parents, etc.
-- I underlined a few weird phrases.

You try to use a lot of detail, which is good. I also like where this is going: a normal girl with a dark secret. Though it does seem a tad bit cliche so I wonder what your twist is. But to be honest, this piece could use a lot of work and it felt a bit sarcastic to me (which I'm sure wasn't your plan).

This story starts with a young, average, American girl named Tiana. Tiana#FF0000 ">, when she was little#FF0000 ">, had the wildest imagination like every other toddler in town#BF0000 ">; her little world was perfect. She had the #FF0000 ">best friends in #FF0000 ">elementary school and would never forget them and never did, but because of her parents jobs#FF0000 ">, sadly#FF0000 ">, Tiana had to move#FF0000 ">. From that point on#FF0000 ">, it was all over for her...the nightmare truly began.

Tiana Anderson was no longer the little girl from across town..she had to go to a different school and meet different people. Those people were not the nicest people in town, the kids she met were raised by beastly parents and never once could she do anything about it#FF0000 ">. By the time Tiana grew older#FF0000 ">, in the 8th grade she was still taunted and teased. No boys liked Tiana, she had very few friends#FF0000 ">, but the ones who were her friends were the closest people to her heart besides her family. Things were about to change for our creative, innocent, loyal and smart Tiana, God had a plan for her. By time high school started she had gotten a boyfriend...

"Too bad he turned to be a lying, cheating snake" said Tiana.
"Don#FF0000 ">'t worry about it sweetheart it wasn#FF0000 ">'t meant to be... besides you can do way better#FF0000 ">," said her best friend Lauren#FF0000 ">. Lauren was the only girl who accepted Tiana before and after she had a huge weight gain and loss. Eventually Tiana gained more and more friends, yet she was still heartbroken in the 10th grade and 11th. So there it is Tiana a senior and still no one to call her own since her on and off dating in the 9th grade with some jerk who took her virginity. She didn#FF0000 ">'t know what was wrong,she was told she looked good a lot and she had the perfect personality, but she guessed that all the guys didn#FF0000 ">'t want a relationship and the ones that did already had girlfriends. But no one knew, no not even us, knew that she had a deeper darker hidden secret, one too complicated for one mind to understand...

Hello!

I can not agree more with the reviewers above me. They made very excellent points about run one sentences and spaces after commas. I'd fix those up a bit, if I were you. Another thing they mentioned was the paragraph size. I'd strongly suggest you to split it up a little bit.

Another thing I want to tell you about is, that another reviewer mentioned is "show, don't tell". That is my favourite advice and I found, personally, that it really does help with my writing. It makes things much more interesting if you tell the reader that the lake was of a calming azure colour rather than the lake was beautiful. If you described it, not only does it keep me more interested, it'd also paint beautiful pictures in my head, which is always good. So, "show, don't tell" it livens your writing up. Of course, when I say "show, don't tell" I don't mean show all the time. Whilst showing is good, keeping the right balance is also very important.

Now, I have some nitpicks and particular parts of the story that I want to comment, here goes:

By time highschool started she had gotten a boyfriend.."too bad he turned to be a lying,cheating snake" said Tiana,"dont worry about it sweetheart it wasnt meant to be...besides you can do wayy better" said her bestfriend Lauren,

Dialogue format. Whenever someone starts to say something, it has to be put on a new line. So that line should turn into:

By the time highschool started, she had gotten a boyfriend.
"Too bad he turned to be a lying, cheating snake," said Tiana.
"Don't worry about it sweetheart, it wasn't meant to be... Besides, you can do way better," said her bestfriend, Lauren.

Formatting it like that looks a whole lot better. It's also what the readers expect to see. So, I get a bot confused if I see pieces of dialogue written in another way than the usual one.
Another I'd like to point out with that piece of dialogue, is the word 'wayy', personally I'd avoid using spelling the word incorrectly, even if that is how the person said it. Unless of course, tif hey had a really strange way or speaking or something. But for little things like that, I'd put it in italics.

before and after she had a huge weight gain and loss

There was no mention of her gaining weight before. I think that it'd be easier for the readers to follow if you start to hint at this in the beginning or do something that won't make it seem to jump out of the blue. Because when things jump out of the blue, I get confused and wonder if I've missed something.

She didnt know what was wrong,she was told she looked good alot and she had the perfect personality,but she just guessed that all the guys didnt want a relationship and the ones that did already had girlfriends

This may just be me, but I find it a bit hard to believe that no one would date her if she had the perfect personality and had looked pretty good. Surely there must be a bunch of guys who have no girlfriends, right?

I did like your ending though, you left it mysteriously so that we'd like to read more. I think that worked rather well. All in all, not a bad try, but watch out for the little things such as spaces after commas, formatting and things like that. Keep it up!