I'd bring what I like to drink. Ask the other mom(s) what they like and offer to bring some for them, too. What you like will inform how you bring it.

I'd personally avoid glass, regardless of what you like, but that's just me. Lots of good wine and beer options on cans.

I'd do those vodka seltzer cans. Less mess and easy to share. Or a red wine if you don't have a mini fridge.