You might be interested in my AGPL federated social network, Jonline, which I've built specifically for this purpose. Source is at https://github.com/JonLatane/jonline, and I have a few instances up at https://jonline.io ("flagship"/demo server), https://bullcity.social (Durham, NC community), and https://oakcity.social (Raleigh, NC community).
It's a pure Rust server so it's extremely lightweight to self-host compared to things like Mastodon, plus it supports events (with iCal/Google Calendar export). I'm also happy to host an instance on my DigitalOcean Kubernetes cluster for anyone interested and integrate it into my CI/CD pipeline, which is an option on my GitHub sponsors page (and I'm working on a load balancer which should eventually bring the cost of this down as well).