Eastern Long Island Beer Tasting Group

I'm trying to start a small beer tasting group. I'm thinking about trying to keep it to harder to find beers and homebrews and keep the age range on the younger side, my bf and I are 26, and most of the people we've talked to are mid-late 20s and early 30s. Does anyone have any advice for starting one? Like what's a good number of people, what's a good way to make sure a few aren't always supplying much harder or rarer beers then everyone else, ect. I be bringing stuff that I've traded for that aren't sold on Long Island or are hard to find here and I would like most people to be doing the same.

 

We're out in Shoreham, another couple we talked to is in Central Islip, 1 person is from Bay Shore and the last is from Smithtown, so if you don't mind it might all be in suffolk I'll let you know as things develop.