How to Add User to Sudoers in Ubuntu

I am trying to better understand sudo permissions under kubuntu.

From what I have read, in kubuntu there is no "root" user, but if you have admin privileges you are able to run sudo commands. If there is only one user (in my case that is true), you will automatically be set with admin account. I have checked in system settings - users and this is the case for me, so I am able to run sudo in a terminal when asked.

My question is, is it possible to be setup in a way that I don't need to run sudo at all, and there are no permission restrictions?

I am writing a python script to build some file structures and am getting the following.

PermissionError: [Errno 13] Permission denied:

After I add a user using adduser, I can't see it via System > Administration > Users and Groups unless I log out and then log in again. Is that normal?

Do you mean you cannot see it immediately after adding without logging out and in - or that you must log out and in every time you check, even with users added long ago?

Package gnome-shell-extension-user-theme-3.10.1-1.fc20.noarch already installed and latest version

will work