A few thoughts on mastodon:
Retoot often. The mastodon network is sparse. Many folks are new, and finding each other is complicated. If you see something you like, retoot it. You are the suggestion algorithm. Everyone benefits.
Follow liberally. We’re accustomed to timelines crammed with ads and unwanted posts. Even if you followed the same number of people as elsewhere, you’d see much less content on mastodon. So follow liberally; everything is more with friends.