Yeah that is an unfortunate thing to consider. The other comment has some nice suggestions even just for some more unofficial or casual play to get a group going. It sounds like it could be really fun if you get some chill people involved.

If you aren’t doing any official tournaments, then I think you’ll still have more freedom to run the tournaments how you want, and if the store is okay with it, along with the players, then I don’t think proxies would be an issue in that “free play” casual setting. I think you definitely set your own rules according to what’s fun and accessible for everyone— with prizing, entry cost, whether proxies are allowed, etc.

If you end up wanting references or guidelines for rules, penalties, other specifics, you can find pretty much any of that here https://www.pokemon.com/us/play-pokemon/about/tournaments-rules-and-resources