Experienced RH users can still use service and chkconfig in RH 7, but it’s long past time to dump them in favor of native systemd utilities. systemd has outpaced them, and service and chkconfig do not support native systemd services.
Our beloved /etc/inittab is no more. Instead, we have a /etc/systemd/system/ directory chock-full of symlinks to files in /usr/lib/systemd/system/ . /usr/lib/systemd/system/ contains init scripts; to start a service at boot it must be linked to /etc/systemd/system/ . The systemctl command does this for you when you enable a new service, like this example for ClamAV: