@
yourlibrarian that's correct. generally speaking, if you want to subscribe to people, you'll want to be sure you have the 'ActivityPub Protocol' enabled on your
apps page. Then, you can search for people who have their homes on sites that also use that protocol, such as Mastodon or PeerTube. (You can also follow people on other Hubzilla servers, as well as Plume and so on.) You'll search for their 'full' name, so for example, if your friend is on fandom.ink as 'myfriend', you'd search here - on Hubzilla - for 'myfriend@fandom.ink' and it would pull them up. Since dreamwidth and tumblr don't implement those protocols, you wouldn't be able to find people using them, but you should be able to subscribe to anyone using an application implementing either ActivityPub or Zot. There's a good reference at
fediverse.party.
(Zot is a separate protocol that Hubzilla uses. It's similar but has slightly different requirements for stuff like logging in and deleting content. Like ActivityPub, it's just another way to move data between websites.)