For anybody like me that has used Linux before usually runs in run level 3 or console only mode.
The problem is that the Red Hat documentation for the developers state that you should setup your instance with the GUI first to get access to downloading packages, etc.
According to the Red Hat documentation, I wanted to share the way to register Red Hat in CLI and provided below is the syntax.
subscription-manager register --username email@example.com --password password --auto-attach --force
Hope this helps!