Most of Centos, Fedora, and RedHat previous users are used to set Runlevel by changing the file “/etc/inittab”, however, the newest version of the Red Hat OS (version 8) changed the way how it is set.
You should use the following commands to perform this change in each scenario.
Multi-user terminal mode (alike to runlevel 3)
# systemctl set-default multi-user.target
Graphical mode (alike to runlevel 5)
# systemctl set-default graphical.target