Hello
If you want that your computer to autologin and is a centos /rhel then you must modify /etc/gdm/custom.conf
Add to that file
[daemon]
AutomaticLoginEnable=true
AutomaticLogin=username
If you stil want to have a delay and after autologin , you must add
[daemon]
TimedLoginEnable=true
TimedLogin=centoslive
TimedLoginDelay=10