How do you find (fun & interesting) accounts to to follow on Mastadon?
On Twitter I mostly followed people I knew in real life, comedians, some novelty and parody accounts. I joined Mastadon and I really don’t see anything interesting to me looking at trending posts and what not. It seems very grown up and dry. I miss a little of the “Wild West” aspect of twitter from early 2010’s with offensive humor and cutting satire and just silliness.
Write an introduction post (and make sure you hashtag it #introduction). Use lots of hashtags in your posts, it will link you with other folks using the same ones. Jokey ones aren't very useful, try to keep them general.
Follow liberally (like the other commenter said, you can just unfollow if they stop being interesting, retoot generously (as there is no algorithms, retooting is the only way posts gain traction (and people will notice if you're retooting them), follow any hashtags that seem interesting.
Also, since nobody else mentioned it, always alt-text any images you shared, not only because it is courteous and expected for you to do so, but it will help you get followers, because many people won't follow people who don't use alt-text.
Oh, and the same goes with content warnings!
It's these little things that make good Mastodon members and will keep people engaged with you.
(You can watch how people who do well on the platform format their posts to validate what I've said).
Mastodon is awesome, I love it. Good luck!
PS: I almost forgot to mention your instance! Check out your local timeline to see what's going on there. If there isn't anything interesting there maybe move to a more active instance, or one that reflects your interests.