On Kbin if the community you want isn't showing in the magazine list, what you need to do is go to the search bar that searches the whole site and type in the Lemmy community name followed by an @ followed by the instance name. For example: firefox@lemmy.ml
After searching it should come up and you can subscribe to it. It only shows up in the magazines list once someone on the instance subscribes to it, so if you are the first to subscribe to it you have to do a manual search first
Yup! No worries! Glad you got it figured out!