Crush question?

Ok so there's this guy in my P.E cl and uhhh.I like him. BUT iono wat to do...yesterday he asked this guy wat my name was and said Hi to me but like I wanna let him know i like him. BUT again...this sux becuz he used to date this girl whos now my friend. buh she don't know I like him but still this really sux wat should I do i REALLY like him! he's been looking at me and stuff becuz he sits right next to me