Hi and welcome to Lemmying.

Old sublemmies exist only coz none clears them, works as archive.

Note, there may be another community of the same name on different instance - c/main@lemmy.blahaj.zone is different main to c/main@lemmy.ml or c/main@lemmy.ca. They all happens on different servers, but single login is enough to reach them all.

If You mean meeting people from lemmy.blahaj.zone directly. Don't.

Are you looking to meet anyone on Lemmy at all? If you look at the "all" tab you should be able to find lots of active communities.

Be the change you want to see: post and comment.

So you mean online friends or offline? There are some success stories of offline meets, but honestly it's unlikely to find someone nearby here, also they would require communicating your location which many people are uncomfortable with (loving in a large city might help). Online friends might be made via PM if you're socially apt enough, I guess. There's also a matrix server if group chats work better for you. Your PMs are encrypted there; I'm not sure if Lemmy offers your PMs any protection from instance admins.