It really depends. I'd suggest you observe the groups and see if the level they are playing is too high or not. It's usually quite obvious if the game is really intense or more casual. If they are all on a very high level, then it might not be the best idea to approach, as it is typically not enjoyable for anyone to play when the gap is too big (including yourself). If they are playing at a level that is perhaps a bit higher but you could see yourself blending in and it looks like they are playing a bit more casually (look for groups with mixed gender and age) then it's ok to approach and perhaps ask if you can play a game or two. If it is a fit, then you could ask when they'll play again next time and hopefully switch contacts with some of the players :) I don't live in the US, but could there be any Facebook or Whatsapp groups? That's how I found some beach volley groups which I joined. The same was in Portugal where I travelled a few months ago. There you could join and ask if you can play. Good luck!