It is best not to use root user for anything as root is a common user name. It’s better to create sudo users for these purposes.
Here’s the easiest way to add a user to sudo group.
First create the user you want:
sudo adduser somik
Adding user 'somik' ... Adding new group 'somik' (1000) ... Adding new user 'somik' (1000) with group 'somik' ... Creating home directory '/home/somik' ... Copying files from '/etc/skel' ... New password: **PASSWORD** Retype new password: **PASSWORD** passwd: password updated successfully Changing the user information for somik Enter the new value, or press ENTER for the default Full Name : **NAME** Room Number : Work Phone : Home Phone : Other : Is the information correct? [Y/n] **Y**
Then add the user to sudo group:
sudo usermod -aG sudo somik
That’s it. Now login as the user.