Hi new people from Tumblr! I hope you're settling in okay. Feel free to poke me if there's anything I can help you with.
One thing that isn't said enough is that, while the fediverse is a nice place, and your hard-working instance admin will help keep the worst elements way, you'll still run into people you don't like. Some people will rub you up the wrong way, or are just butts. That's okay! Mute, block, whatever and carry on. Please don't get disheartened because it's not perfect.