I never really used twitter, but since mastodon is the FOSS version that people seem to like, I've been trying it. But it's kind of hard if you don't know anyone to follow ¯\_(ツ)_/¯ .
Anyway, any suggestions? It doesn't have to be necessarily about leftism, just people you find worthwhile to follow.
@yogthos@mas.to is a good follow for leftist stuff. Posts a lot of good stuff, and reposts (boosts) a lot of other leftists which makes them a great way to discover more people.
toots.matapacos.dog is a leftist server, so looking in the local timeline there is another good place to find people to follow.
Remember that to follow someone on a different server, you can't click 'follow' while on the other server's page. Search for the user (@username@server) to get them in the search results of your own server pages, and follow from there.