The onboarding will offer you a lot of topics to sign up to. These contain communities in them. The idea is to populate subscription feeds, however it can leave some users with a lot of undesired subscriptions if they click too many.

If you wish to roll this back. Go to Settings -> Profile and click the yellow bar. Don't click the red bar!

But welcome, and feel free to post your thoughts here.

!newcomers@piefed.zip for a specific community also devoted to new users to the Fediverse.

Come Join us in the Zulip Chat if you have specific queries.