Just wanna say I agree - it can be a frustrating process to figure it all out.
In some cases, trying to follow a user takes me to an error page, and repeated attempts prove unsuccessful.
This confused the fuck out of me until I realized that Mastodon instances have the option for users to allow or deny follow requests. Basically, if you click on someone's follow and nothing happens (or you get an error page), what's happened is that you've sent them a follow request that they have to approve. Kbin's interface fails here (hopefully will improve with update) and does nothing. If they do chose to let you follow them, you'll see their account update.
In some cases, I can't even find particular instances that users post from via kbin.
Go to the poster's account, and follow them. If Kbin hasn't actively federated the site yet, it usually does so pretty quickly after a follow. This usually also lets you link to the community they posted to.
Check your magazine's Microblog section - you may be getting more content than you realize. Your magazine tags will determine what additional content (aside from #yourmagazinetitle) your Microblogs pick up. Everything from Mastodon users shows up there on Kbin.