Need advise help please!!!(10 points)?

Ok so there's this girl that likes me I know because she is complementing me I catch her staring at me when we get a chance to talk she always looks into my eyes and smiles but there's a problem we don't talk Mutch only last period in English 10 class I have 3 classes with her and I just really don't know what to talk about when I'm around her I and like when we have some free time in my class we just sit and do nothing sometimes she will look behind her to her freind ( it's a guy not boy friend ) try to Lisen to his conversation and join in and I think that if I don't start having more conversation with her or hang out with her I'm going to lose her but really can u give me some conversation starting examples plz!!!