Um...the OP says she may be getting a horse that's never jumped before and she wants to teach it to jump.
Again, WHERE ARE HER PARENTS? As in, why would they even be contemplating purchasing a horse for their daughter that isn't already extensively trained? What parent thinks their 13 year old daughter is anywhere near being educated and experienced enough to be undertaking such a task? It's not like the OP was born and raised around horses.
That isn't being harsh. It isn't being told off. And it's entirely constructive.
And I most certainly know w/o seeing the OP ride, that she's not anywhere near ready for such an undertaking.
I've said this before...'this' isn't a game. We aren't teaching a poodle how to sit.
Either this is a made up story, wishful thinking, or a serious disconnect between parent, child, and the reality of owning and training a horse.