Pretty simple and quick way to add a user to the sudoers list in fedora:
Login as root user:
su
Password: *enter root password here*
Add write permissions to the sudoers file:
chmod +w /etc/sudoers
Add the user (change alex to the user you want to add to sudoers) to sudoers and set no password (so you don’t have to enter a password when using sudo).
echo '<strong>alex</strong> ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
Remove the write permission from the sudoers file once you have finished writing to protect it, and then exit:
chmod -w /etc/sudoers
exit
Now try testing it out by checking for updates or anything else you need to do as root :-)