Front page side bar usually shows rules. The others there is no simple way to find out in advance.
My point was that it DOES matter where you create your account, beyond just getting a name you like. So I expect many people will hop around from instance to instance until they find "home".
That's fair. I do think bouncing around right now isn't too bad. Sign up is simple and names are available. It could be harder later when name choices are slim or sign ups require more effort.
Whilst it's all part of the fediverse experience, I think there needs to be a much lower friction workflow to migrate users, even if banned, to reduce the cost to a user of disagreements with mods that can't be resolved harmoniously on an instance.