Are blowjobs normal?

Personally irl whenever blowjobs come up in conversation (which is rare) every girl I know (me included) aren't willing to do blowjobs, but on the internet and in shows I feel like its the opposite case and they're treated as not only normal but like its weird not to do them. Are guys genuinely upset if their girlfriends dont agree to give blowjobs? Sorry I feel like all i know about sex comes from this site unfortunately and Im kind of concerned.