You two sound very compatible already and it's good that you have common interests.
I agree with the others, you don't have a reason to believe he has a gf but I'd also spend a few more weeks really getting to know this person.
One main sign that someone likes you is eye contact. Do you catch his eye from across the room? Does he glance away when you do this? - if he looks back at you again that's a good sign. If he smiles when he looks back at you, that's a really good sign.
Also, when talking to him, usually if people are interested in what you are saying, their attention will be focused entirely on you. Eg they won't constantly glance at the clock, play with their hands or stare down at the ground ect.
If they are interested, they'll copy your body language and his body will be facing you. Like when you fold your arms - does he fold his?
See how things go before making a move
Good Luck!
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