In all honesty... I don't want to make this come out wrong, or offend you, or even hurt your feelings. Personally, I think you should get the feel of WattPad before you start writing. I've seen your story and I think it sounds like it has a great plot, but I don't think your ready to put that into words yet.
You should read some stories and compare them to yours first, so you can improve them and make them what you see in your head.
Take awhile to think about it. Don't make the mistake I did. I just posted stories here and there when an idea popped into my head. I just ended up changing the plot numerous times until I was satisfied.
So think about it before you post it, and look up some tips to help your writing. -Aubrey