So there's this guy that I like and he has a girlfriend. And they're having long-distance relationship. Should I give it a shot?

I don’t think you should give up, but at the same time, I don’t think you should get between their relationship. You can still like him, and talk to him, be with him, and see if he likes you back. But don’t flirt or be all over him or anything that could hurt his relationship. It’s in bad taste and very disrespectful.