Minikube is related to kubernetes, which isn't exactly virtualization but rather, containerization. Those two things are different.
And you don't do VM in a VM, only very special circumstances allow for such a thing
Qubes isn't exactly the best option for what you're looking for. If you're looking for an ideal OS for minikube then go for Alpine Linux and as for miniocp, maybe go Proxmox VE or VMWare ESXi?