First start by creating the user from your root account (This command will prompt you for the password and other user related information):
root@yourdomain.com:~# adduser username
Next type the following command and hit Enter:
visudo
Now look for the section where you see root ALL=(ALL:ALL) ALL. We want to duplicate this line for our new user we just created so the type the following just below that line and save your changes:
username ALL=(ALL:ALL) ALL
Now login as your new user:
ssh username@your_server_ip_address
