When it comes to instances there’s no “right” answer for everyone. Pick one that you enjoy, that you identify yourself with, that you don’t distrust the people in charge, and that is neither shitting its pants nor overly large. This site might help you with that.
I can’t recommend an app.
Define ‘weird political shit’. Because Mastodon is also full of weird political shit. The election years are unbearable.
Yeah why would you go on a microblogging platform if you didn’t want to see “weird political shit”?
I’d go for stability. Smaller instances can be slow. If you want fast load times use a bigger one, like mastodon.social
Tusky is a great droid app. And I would suggest one of the big official instances. If you hate it you can transfer your account/profile to another one. Your posts don’t transfer though.
Bluesky isn’t a terrible Twitter alternative, but it’s not federated. Mastodon is fine, but I’ve had a much harder time staying engaged there.