This virtualbox tutorial will show you how to install Virtual box Guest additions on CentOs 8.

When this process is done you will be able to make CentOS 8 full screen in Virtual box, so in affect the video shows how to make Centos 8 full screen in Virtual box.

The command that i run to download the relevant packages are:

sudo yum install tar bzip2 kernel-headers perl gcc make elfutils-libelf-devel