Meetups are a great match! A communikey needs a relay (self hosted or not) and optionally blossom servers and an ecash mint.

For creating one, log in to chachi.chat with the meetup pubkey, click on "New group" and select Community. There you'll be able to configure your relay, blossom and mint settings. After creating it, open the community settings and you'll be able to add content section (tabs) with the content types you want displayed!