

If you want to play with Atomic distros I’d recommend you do that in a virtual machine in KVM first. They are quite restricting which is good for the distro developers to make consistent releases and experiences for users, and secure, but not necessarily the best option for tech savvy users.
There are ways around the restrictions but you can reach points where the compromises you have to make are too frustrating. If you find that out late down the line after setting up your desktop it can be very annoying. Also I do use Flatpak, but it’s not the most efficient way to run software. Atomic distros have more overhead due to the need to use flatpaks or distrobox and the like to get everything you might want.
Atomic distros are a neat idea but I personally love tweaking every element of my install and optimising or customising it. So I use a rolling release distro, have my home folder on a separate partition, and back up regularly.
Some good advice already in this thread.
Also worth considering QEMU as an alternative to VirtualBox. The Virt-manager tool is decent way of managing machines, and it’s relatively straight forward to create a base machine if you’re duplicating it. Virtualbox is perhaps initially more user friendly for absolute beginners, but once you have any familiarity with virtualization I’d suggest QEMU offers much more.
Also I find integration between the guest and the host linux system is generally more straight forward. Most linux systems already ship with samba and other relevant tools QEMU uses to interact between host and guest. There isn’t a need to faff around with the guest-additions stuff. Plus KVM virtual machines can run with near native performance.