where can I ask qestions about self-hosting the builder?

Is it possible to define CSS classes via code? The main reason I ask is because I want to have one class name that does 2 different things depending on if it's on a Button or a Link

or, do I even need to? are the limitations just when you're hosting the site on the cloud?

im a bit confused, im sure there's a nice helpful page for it: how do I selfhost the builder?