Hang in there! I highly recommend using something like https://lemmyverse.net/communities to search for communities. Lemmy (and most other parts of the fediverse) are a double-edged sword: you’re not being algorithmically fed content, so you’re able consciously curate what you devote your attention to, you’re not being surveilled for marketing, etc. However, because of this, it’s harder to accidentally find an interesting community because they’re not actively presented to you.
I just started using the search above to type in keywords of interest. I’ve found some established Lemmy communities I don’t think I would have stumbled across otherwise.
I’m curious if anyone else is able to provide an example here. Personally, I grew up in an extremely right-wing, very isolated, very culty version of the southern baptist church. I was around young-earthers, anti-vaxxers, anti-evolution folks, dinosaur/man co-existence, believing black people are black because they’re cursed—all sorts of crazy whackadoodle shit. I never once met someone who didn’t believe in space. I think you’re right that this was a YouTube Fact™ that she picked up somewhere.