If you need to use virtual machines on Linux, try Virt-Manager. Virt-Manager is more reliable than VirtualBox. Virt-Manager is completely free and open-source. I'm a long-time supporter of VirtualBox.
Loading up virtual machines is an easy to accomplish task, but configuring them properly is an ongoing balancing act. It’s very likely that in a virtualized environment you will over/under provision ...
I found the best Linux server distros for your home lab ...