I love a girl

I am in the same classroom with the girl i love and ive loved her for 2 years but i never said anything to anyone(you know friends can get very annoying ) and the main reason is that im afraid that she doesnt like me back so ive been observing.I see her everyday but she is not one of my friend (im not so socially active) and every now and then she looks at me, i dont know why but i think that she wants to see if i am looking at her.Amd another thing i dont undestand is: why does she always say to me before asking a question: (my name) you know everything so can you answer... but i think she says this because im the best student or because she is an opportunist.So i thought maybe she loves me but recently she did another thing, our philosphy teacher organized a debate and i partecipated and when it ended he asked our class who won the debate(the teams were composed by 3 students) and sge voted against me.What should i do?i dont know how to talk to her(she just ask me some questions about school) and most importantly i dont know if she likes me.