Mastodon is different. It's polite and friendly. There's a different code of conduct (please look up some of the basics), a slower pace. It's not a sprawling, hectic shopping centre in a grim industrial park on the city rim; it's a pleasant village street with artisanal shops and cafes. Take your time. Be nice.

3/ If you're from the #TwitterMigration, don't make the mistake I made at first : talk to strangers instead of trying to recreate your Twitter timeline. Open the local and/or federated timelines and talk to people. Say nice things to cat pictures. Roast Twitter with someone. Welcome another newcomer. Most people are cool and nice (and you can make sure you are one of those people too !) so take advantage of the general atmosphere to build something breathable.