This article describes the "hands-off" installation of Oracle Database 18c RAC on Oracle Linux 7 using VirtualBox and Vagrant with no additional shared disk devices.
If you are comfortable with VirtualBox, Vagrant and RAC you might want to jump straight to the GitHub repository and use the basic instructions here.
◈ TL;DR
If you are comfortable with VirtualBox, Vagrant and RAC you might want to jump straight to the GitHub repository and use the basic instructions here.