It's a great start, but PLEASE, break up the text into paragraphs and do some spell-checking!

Oh boy.

prettyprinsses5

should be 'prettyprincess5' (side note, I've never had to proof a person's username before.)

Rainbows Stripes

should be 'Rainbow's Stripes'

Rainbows colours didn't come out from no where. Her incrediable speed was a story that started young. We follow her distant past to find her true identity of which she became today. Somepony challenged her and that challenge led her to find her destiny Which later becomes a phenominum that all the ponys of equestria shared.

should be "Rainbow's colours didn't come from nowhere. Her ability to reach incredible speeds is a story that started in her youth. Join this travel into her distant past to see how she became the pony she is today."

You want your description to be short and snappy. Watch your spelling and grammar while you're at it.

~Midnight Dancer, TWE's cranky grandma

Grammar check! Nice choice of words, however. Yes, I agree with Kwisatz-Haderach at that, and some cannot simply stand bad grammar.

Grammar Nazi to the rescue!

Yes I understand that, I'm practicing my grammar everyday God why does dyslexia hate me? But I'm glad you enjoyed it.

>>14523021452302   Ahhh thank you that actualy sounds so much better, I just write words that come into my mind, thank you so much for correcting it. Im sorry about spelling and grammar I tried so hard to perfect it I forgot the key elements of writing a book/fanfic....infact this is my first fanfic. I shall make sure my next fanfic is up to a higher standard but I'm glad you took the time to read it, and I hope you enjoyed it.

>>14523021452302  Oh and also I was about  9 when I made the name prettyprinsses5 XD I do know how to spell princess but back then I didn't but I remember it well.

>>14572841457284 One of the best things to do when you're submitting to this site is to get an editor/proofreader to help you polish it before you publish ^^

>>14573361457336 Brilliant Idea XD thank you for the tips, I write proper books but it's a hobby so I need to sort the proofreading out. I guess I just get too into the story and forget things hehe xx I shall improve XD