I haven’t ever used a VM though, will I have to set it up every time, or can I save the VM and start it up whenever I want to?

It's just like a physical machine, except launched in a window from your desktop (or wherever you put the VM launcher). And yes, if you set it up correctly, it saves its state when it shuts down.

I use virt-manager, which is just a GUI on top of KVM/qcow. Works really well. It's available for pretty much every Linux distro.