That explains why I don't have the create community button then. So do I just create an account on another instance and then create? And how do I know what instances I can create a community?
So do I just create an account on another instance and then create?
Yes, you can do exactly that.
how do I know what instances I can create a community?
There's a "Create Community" button on the header of an instance even if you aren't logged in or don't have an account. But if there isn't one (like in lemmy.ml and beehaw.org) then that means you can't create a community there. You might need to request for one from their respective admins.