@MelodicDinosaur Welcome to the Fediverse. Mastodon might be just the place for you. Take the time to search for and follow users and hashtags that you're interested in as it works best once you've curated your feed. Also don't be afraid to boost things as this also helps with engagement.

From my experience so far, Mastodon is a pretty inclusive place with regards to neurodiversity and nerdy stuff like Linux etc. That could also just be my personal experience based on who I follow, but I'm sure you'll find some engaging topics.

You basically get what you give so don't hold back.