from my experience there are some decent communities and people on FB, it's just that you have to find them hidden under heaps of bullshit. No different from Reddit, Twitter or YouTube in that sense imo
With something like Lemmy though, both the users and community moderators have way, way more agency over what they're interacting with, so I don't think federating with mainstream social media would necessarily be that bad
I think, at least?
Not to sound like I'm saying "just learn it lol" but the coding required for simple website building is probably 1000x easier and quicker to learn than you think it is, even if you're like myself and have both a learning disability and a babylike grasp of math and formal logic
Learning a bit - just the bare minimum - will probably open up your options a ton. Most of the answers in this thread are already more DIY than what I'm guessing you're hoping for anyway