Generally, there is no GUI in Linux Servers and if you want to install Oracle database 19c or weblogic server etc, you will need VNC Server.
If you install VNC Server then you can connect to Linux server and use GUI when you install Oracle database 18c , 19c or something like that. You can install VNC Server on Oracle Linux with below yum packages.
yum install tigervnc-server yum install xterm
yum install twm yum install xhost