Yes, Virt-Manager does have a slightly steeper learning curve than VirtualBox. (I'll write an article soon on how to create a VM with Virt-Manager.) However, the reward for getting up to speed is a ...
ShaniOS maintains two separate environments. If an update - or anything - goes wrong with one environment, simply reboot and switch to the other.
Familiarizing yourself with Proxmox will help you in the long run ...