treat it like meeting new people offline.
- go to interest-based meetups (
: tag search) (bonus: you can't get covid from tag search, unlike physical meetups) - get your friends/acquaintances to introduce you to new people (: reblogs)
comment on interesting posts to strike up a conversation! also, assume good faith until proven otherwise, we're mostly all trying our best over here. welcome! 
Be generous with your follows! Twitter has conditioned us to be extremely scrupulous about who we follow in order to keep our ever-flowing timelines somewhat manageable, but happily Cohost is a far slower-moving beast. (I know the timeline's popping right now with all the new arrivals, but things will settle down in a few days.) This is a great opportunity for you to follow people who might have a vaguely interesting hobby, or who wrote a neat essay, or who just seem nice (the welcome to cohost tag is great for this). Plus, if you enjoy the site and want more people to stick around, giving folks a follow is a great way to make them feel like they aren't just posting into the void.