Hi,
The distro agnostic answer is to use the command line. As I don't know Zorin, I'll talk you through doing it that way.
You need to be root. From a terminal emulator, either type
followed by your root password or
followed by your user password if that's how Zorin works.
Now run
and then hit enter.
Now run
and enter to set a password. Obviously, replace <new_user_name> with your new user's username...
I'm sure there's a way of doing this in some admin GUI but the above is the (hopefully) definitive way of doing it.