Third time's the charm, I have a booted #NixOS VM. 🎉
Now what.
In case you want a piece of unsolicited advice:
When a friend of mine was doing the same half a year ago, I suggested that they install nix on some system they already use and always remotely deploy into their nixos vm/machine and I think it worked out well. (That setup is both IMO simpler conceptually, and is closer to what you'll want to use if you end up using nixos for some machines of yours in the future.)
@robryk yeah, start playing with it and understand it. Maybe start using it for something.