I thought we were all one big federated family but I don't have a deep knowledge of how it all works. I'd like to follow accounts like lowqualityfacts and Georgetakei but I can't seem to find them by searching.
I wish you could, but for all intents and purposes Lemmy and Mastodon aren't part of the same fediverse. Kbin/Mbin let you follow accounts, and I think !tails@lemmon.website automatically turns toots from some accounts (including Takei's) into Lemmy posts.