Like my old best friend, don't know what to do?

So I became friend with girl when I was back in seventh grade. After a couple of months, I really started to get attracted to her. I told her friend that i like her.(bad mistake) I figured if i had aks her out back then maybe she would have said yes. Now I'm in ninth grade, going in tenth in september. In eighth and ninth grade, she wasn't in any of my classes so we never talked much. Now when she see me, she always smiles. She said "hi" everyday if i see her. I think it probably a friendly thing but i'm not sure. Even if i try to make eye contact with her, she always seem to see me. I don't know what to do? I still like her..