How do you know if a guy likes you?

I’ve been talking to this guy a lot for the last couple of months and I’m really starting to like him. For the most part, he seems to act like he likes me. He always hugs me in the hallways at school, he jokes around with me and flirts with me, and the other day he even ate lunch with me (which he has never done before). However there are certain things that make me doubtful. First, he has said “you’re like one of my best friends.” Which scares me because he basically friend-zoned me. And second, he has mentioned an ex girl of his a couple times.

Do you think he likes me? I can really see myself with him, but I’m not sure if he feels the same. He acts like he really likes me, but I still have some doubts. What should I do?