Welcome! I typically say that the Threadiverse (a decent all encompassing term to mean "reddit format" e.g. link aggregator type social media that includes Piefed, bin, Lemmy etc.) is about where reddit was 10-15 years ago.

I recommend lemmyverse.com for comm discovery, sometimes your might be looking for a comm that does exist, but for whatever reason your instance just hasn't picked up on it (typically someone from your instance has to manually go to a new comm and sub to it if your instance missed the automated bot federation from Lemmy-federate.com

We’re not without our cons though, biggest problem we have are probably the Tankies, but here they’re mostly on what's known as the Tankie Triad: lemmy.ml, lemmygrad and hexbear. For the most part, grad and hex are widely defederated from (Users and content of those instances won't be "synced" and you won't see them) and you only have to worry about .ml, but on Lemmy you can do a personal instance wide block if you’d rather just not deal with them. .ml tends to be more subtle opting for censorship of dissent before things get crazy on their threads and allowing certain propaganda to flourish (If you wish to see documentation of it, checkout !meanwhileongrad@sh.itjust.works ) or the megathread here (is .ml centric specifically) Here on Lemmy all moderator actions are public and available for viewing on what's known as the "modlog".