There is some federation, however most instances that I’ve seen are people’s personal instances because in the past you’ve still needed a bluesky invite to federate with the main instance. Now that you don’t need an invite anymore I’m sure that’ll change and you’ll see more public 3rd party instances popping up.
Does this run on a raspberry pi 1 or 2? I can’t remember which one I have, but I barely use it so it’d be cool to have something to use it for.