Sixth Grade (I think that's Year 7?) is too young to be dating. You're, what, 12? 13? Anyway, that's too young. And you can't force people to like you. All you can do is be yourself. If you really want her to notice you, try playing sports around her, maybe invite her to a game, but don't try to show off or else you'll probably lose focus and trip up or something. Be prepared to laugh at yourself if things go wrong. That'll show her that you don't take yourself too seriously. Good luck :)