Joining the fediverse can be a daunting proposition, and it is understandable that many end up on larger more centralised servers that are easier to find. I have also had some bad experience with smaller servers also. The first one I arrived on was very quiet, almost inactive, and I should have taken that as a warning sign. Later it went down and I had to join another. Unfortunately the next server was mastodon.lol and so within a year I had to deal with the drama of that one shutting down. At least this time I had six months notice to migrate.
But bigger servers have their own pitfalls. It is easy to get lost in them, being disconnected from the admins. Many are poorly moderated and willing to federate with problematic instances that increase your chances of encountering more explicit forms ablism, racism and queerphobia. And in recent weeks we have seen the willingness of these larger servers to connect to a new service made by Meta, Facebooks parent company, with the onslaught of bigotry that will bring.
So whether you are thinking of joining the fediverse, or are already here but thinking of either migrating or forming other accounts, this guide is for you. It is also for you to share to queer friends that want to join.
Feel free to expand on this list with suggestions in replies. I will try and keep it up to date with which instances are open/invite only, if people can help me notice.
Microblogging (Twitter like interfaces)
Mastodon
The most popular microblogging software on the fediverse. Good app support
https://queer.af (run by Erin who helped draft the ActivityPub protocol the fediverse depends on. I think she is a German trans woman? I might be remembering wrong. Will edit if someone clarifies. NOTE: the .af domain is Afganistan, and these domains will no longer be available to register or reregister, so this instance will likely end up with a new domain name in the near future.)
https://peoplemaking.games (admin is bi and genderfluid, but server is for those involved in making games)
Invite only
You might need to network with admins or users of the following instances to get an invite
https://weirder.earth (all LGBT admin team that includes nonbinary, bi, aroace, queer, transfemme representation, many also adhd, autistic and one light skinned black)
Can use Mastodon and Misskey apps to connect. I use Milktea (a Misskey app) for mobile notifications, but the generic web interface in the browser is so good I usually go there for interaction.
https://blahaj.zone (run by the two Australian trans women that also run this server)
Thanks, that is interesting. However since it remains unfederated, I won't confuse people by putting it in the fediverse guide. I am glad you have included it as a reply though.