So this boy in my class said to me, "notice me senpai". What does it mean? I think they like me, so does that have anything to do with it?
He wants you to notice him because he has a great admiration for you ^^
Senpai is an honorific used for experienced or older colleagues in a organization, like clubs, businesses or even schools.
All of this maybe means that this person considers you as a more important person and hopes to get attention from you.