Probably, though you may have to dig to find them. Lemmy is rapidly becoming like Reddit in that if something exists, there is probably a community for it. If your local search doesn’t bring anything up, I would check on lemmyverse.net. It seems to have indexed most if not all of the current communities. A quick search just now for “liberta” pulled up roughly 10 communities.
Well, first thing, you should read “allow list” as “federate ONLY with these instances”. Block list is the opposite of that, “DO NOT federate with this instance “.
Try removing everything from your allow and block lists and see what happens.