I have a new Lemmy server (lemmy.todayyoutomorrow.me) and I've noticed only communities I subscribe to show up.
The idea was to have my own local instance but I don't see how I can find new communities without using another instance first and finding those communities there and then manually adding them to mine. I have found the following two github projects:
The problem is you lose the ability to encounter new communities by browsing "All". And since I'm the only user on my instance I will never discover any communities that I don't manually add or find on third-party websites not to mention that process of using those websites is cumbersome and tedious...
I added the top few thousand communities and the server runs absolutely fine. :)