The Fediverse doesn’t do algorithmic pushing and that’s a feature, not a bug.

The main ways to find new stuff on Mastodon are all actions taken by you, the user:

1. Hashtags. Watch and follow hashtags you like. Hashtags are the main way stuff is categorized, and if you use them liberally on your own posts and find others posting to those same tags you can find accounts which align with those interests of yours.
2. Home. Check out stuff in the “home” timeline which will be your neighbors on your own Mastodon instance. (In the case of general instances this isn’t so helpful, but in those instances themed around a hobby, subculture, geographical area, etc. you know you have that common ground with your neighbors to start with.)
3. Boosts. When you find people and accounts to follow, they boost things they like, you find things among that to boost, etc. like a friend at a party introducing you to their other friends, friends of friends, etc. leading to your own circle of friends increasing.

All these are things you do and you have to put a little work in to make them happen, but it’s purely fueled by your own interests and wants instead of the traditional social-media algorithm which does a little aligned-interest stuff but is mostly powered by whoever has money to pay the platform to force them into your timeline. On Twitter or Facebook you get shown what the platform thinks they can get paid by showing you. On the Fediverse the rules of invasive centralized ad-choked personal-data-harvesting social media don’t apply; you get shown what you actually want and request.

It’s different and change can be scary, but when you get used to the idea that things don’t have to work the old way anymore it can end up being a good thing.