After some more research I better understand how federation on Lemmy works, and can give you a step by step guide to be able to expand into communities on other servers, no matter where they may reside, very similar to Reddit.

  1. Find a community you are interested in. Go to https://browse.feddit.de to see an index of all Lemmy communities on all instances. Search for what you’re looking for there. While you can browse the community by clicking on it, you can’t subscribe there.

  2. Note the community ID and server. On browse.feddit.de, the top line of the box is the community name, such as ws_server_announce. The name is under that, such as WetShaving Server Announcements. The server is under that, such as sub.wetshaving.social.

  3. Return to your account at sub.WetShaving.social. Click the magnifying glass. Make sure that the search type is All or Communities and everything else says All. Type !communityID@communityServer such as [email protected]. Give it a full minute before becoming annoyed. If our server has never connected to their server before, it’s doing a first handshake and then will start indexing.

  4. If you chose all, some comments may appear. You’re looking for the thing that looks like what you just typed, typically at the bottom of the search results.

  5. Click on it and subscribe.

This is really important because the more servers we subscribe to, the more we and they get indexed. So the more people’s comments we can see, and the more people that can easily find us. So subscribe away!