You discover other users by slowly walking the graph from the people you know and you find the first users in the communities you like through hashtags. It's sl

You discover other users by slowly walking the graph from the people you know and you find the first users in the communities you like through hashtags. It's slow but you eventually build up a pretty good list of people to follow. Also you generally join a server oriented around the subject(s) you like so you can check the local toot stream for people to follow.