Im literally so confused!!!!!!

Ok so im 13 and I like this guy. We had science and band together(end of the school year!!! Going back in August!!) Anyways he asked me to be his girlfriend and I literally froze...But the other day he said that he was only messing around bc he said a few sexual things to me. Im sorta used to it bc guys say things to me all the time. But then he said that he liked me again.......idk what to do I see him tomorrow for summer band..... please help me!!!!!!!!!!