There’s a lot of good info already in here. I’d also recommend checking out the trending post tab, that’s where you’ll typically find some of the posters with the highest number of followers (“hubs” in the Mastodon zeitgeist). I’d also recommend that you follow Lisa Melton https://mastodon.social/@lisamelton. She boosts a ton of stuff and almost single-handedly acts like Mastodon’s algorithm. Her boosts will give you lots of cool accounts to follow, and at the very least will populate your timeline.

If he’s referring to Lemmy.world he’s wrong. Lemmy.world has a different admin who’s not connected at all to Lemmy.ml admins afaik