How do I know if this girl likes me/I have a chance?

[Sam]

So I have a huge crush on this girl for like a year now, I liked her a lot last year because I saw her every day but after summer started it kinda went away and I dont have any classes with her this year, but a couple days ago I saw her and we started talking a little and I can't stop thinking about her. I really like her but were not in the same league, I'm more of a middle person (not a nerd but not a jock) I hang out with some cool people though. She is really popular and hangs out with the popular girls and boys. We're both softmores and both 16. I can't get myself to even say "hi" to her on Facebook because of my stress condition and I have really bad anxiety about it. She has always been really nice to me, she also teases me about inside joke a lot. Last year she would play with my iPad a lot and take pictures of herself and took one of me, she also went on my twitter and made it follow her. I have no acne and I work out ever other day, I am pretty muscular. Please give me some advice. I really like her, I just don't wanna make a fool of myself.