@tealturtle, I was thinking a group could be just be an account, you join the group by following it. You then get announcements about events.
Perhaps some formatting convention could be used to allow date and location to be extracted from a toot.
Then a custom bot could watch for these toots and export a calendar page. Another could suggest related groups by analysing the network of followers. etc.
A Fediverse instance for people interested in cooperative and collective projects.