Whoever you find interesting. Find a cool post and follow, then find another. If they turn out to be boring, unfollow. There honestly isn't a cheatsheet for optimal following.
Is there a post that details users who have lots of followers or who make posts with certain tags? I'm just not used to this model at all, and after knowing about the site for months, I finally decided to familiarize myself. I'll do some poking around.
The community page https://hubski.com/community has a couple different lists of users based on how much they post and how popular the posts are. As well, the "most badged" people are mostly the most followed users. The https://hubski.com/tags tags page shows most used tags, too.
Just a way to say what's going on in your life, hence "pub". Talking about something new with you and maybe sparking some discussion about it.