Ask co-worker to hang out outside of work?

Okay so, the other day my co-worker asked me if I’d ever been surfing. I told him no but I wanted to and needed to find someone to teach me. Later on in the day he was like “oh I have a few boards if you ever wanna go” and I was like “oh yeah will you teach me?” And he was like “yeah! Well have to go on a day we’re both off obviously” so then he checked our schedule and said we’re both off Tuesday and Thursday. Then I was like, well my number is right there on the contact board. So he went over and put my number in. I told him to just text me then we started talking about other stuff and I left for the day.

He hasn’t texted me but we work together again today. Should I bring it up again, like “hey so you wanna try to go this week?” Or something.

Also I was wondering, is it weird to just straight up ask him to hang out.

We both get off at 7 today, I was going to say “do you like boba tea?” Or something lol and then ask if he wants to go get some when we get off. Or ask what he’s doing after work and ask if he wants to go do something. Is that casual?? Lol how do I do this??

(ya I obviously have a crush on this guy. He is also quitting in a couple months so don’t come for me about not getting involved w co workers. Even if nothing comes from it id still like to make a new friend!)