Climax

So I don't have a boyfriend but I have this fwb and we've been on and off for like 2 years. We go to different colleges so when we are home, we hook up. We don't have sex cause I'm not ready to do that yet, but we fool around. I'm not too good or familiar with the sexual stuff even at this point, but I don't seem to cum every time we hangout and idk why that is. Like everything he does feels good and turns me on but I can't seem to cum. Any tips on why or how to actually climax without sex?