Just a quick precision on the root account.
- There is a root account.
- It has a root password.
- You don't know that password and nobody does (it's set randomly during the install)
- The first user account you create is a sudoer. This means he can run anything "as root" without "being root" by just prefixing his commands with "sudo ".
So to be precise the root account is not blocked as such, but the OS tends to push you to use sudo instead of using the root account itself. Good practice that's all.
The reason behind this is that it's more easy to forget that you're root and run normal user stuff under the root account, than to forget not to type sudo ... since typing sudo is a bit of a pain
Of course, if you want to do things the stupid way... or if you need to access some env stuff and can't do it through sudo, you can become root :
sudo su -
or even set a new root password:
sudo passwd root
and then become root:
(then root password).