If you keep going to the same things you can slowly befriend people at them

Asking people you just met or have only seen once for their contact info can be pretty awkward, but sometimes if the click is super good it isn't weird at all. If you've seen someone at least twice and had a positive interaction centered roughly around the same thing(s), it can be a lot easier to be like, "hey, any way I can keep in contact with you? Always good to have someone to talk about xyz with".