The official lemmy documentation isn't very user-friendly I believe!

I personally prefer this Guide to finding Lemmy communities.

There are a bunch of other servers with existing communities set up - you can connect to them from here with your startrek.website account.

Searching them is a tiny bit tricky - if you're the first person here to search for it, it won't show up because that server hasn't connected to this server, so go to https://browse.feddit.de/, find communities you like, and connect to them using:

startrek.website/c/@

e.g. to connect to the Music community at beehaw.org:

startrek.website/c/[email protected]

If you're the first person to connect, the subscriber stats are all wrong (and some posts may not load). Give it a few minutes and refresh. I've seen subs jump from 6 subscribers and 0 comments on every post, to 300+ subscribers and 20+ comments on each post.