Guy advice please!!!

I kinda like this guy I work with , I started working at this new job about 9 weeks ago, at first he seemed interested he asked for my Instagram , snapchat but not my number lol .. I honestly can't flirt nor do I ever have something to talk about but I can say that I do try!! He's very handsome but I'm extremely shy to try and hit on him and crap , there's also this problem with the age haha there's a huge gap (at least I think and my mom will also) he's 23 and I'm 18 in college and everything. can I just get some advice? :/ i get confused as stuck up because of my appearance but I'm again "shy" and don't have much of a big self-esteem as people expect from me because I don't see what they see... I always shut down when they're  really good looking because I feel as if I wouldn't have a chance 😫