When I set up Ubuntu system for the first time, and create first user, will that user be
root? I would like to use
sudo user, so how to add it if first user is
root? Also is it possible to create
sudo user withoute
The first user won't be root. The first user will have sudo permissions. So just install Ubuntu and you'll have exactly what you wanted.
The root user will be created behind the scene, but root login will be disabled.