First, I know this must be the a question asked so often, that you could not count it's duplicates. But all I found here has not solved my problem.
How to activate the root user after a fresh install and give him all privileges sp that I could delete the 1001 user after that.
This is to recreate a server environment created with ubuntu 14.04 where only a root user is active.
To activate the root user run
sudo passwd
in terminal. Enter your sudo password to proceed. You will then be prompted for a new Unix password.goto "system settings" > User Accounts
click "unlock" and provide root password
create an user with "Account Type = administrative" and set suitable password
delete the unused account you want.
Ok, Then Try
$sudo su [ENTER] //IT WILL PROMPT FOR PASSWORD GIVE THE ROOT PASSWORD
TO CREATE NEW USER AND SET PASSWORD FOR ACTIVATE NEW USER
$ usradd username
$ passwd username
TO CHANGE ROOT PASSWORD
$sudo su [ENTER] //IT WILL PROMPT FOR PASSWORD GIVE THE ROOT PASSWORD
$passwd //IT WILL PROMPT FOR OLD PASSWORD IF YOU PROVIDE IT CORRECTLY THEN IT WILL PROMPT FOR NEW PASSWORD