The proxmox interface let's you make the containers, but you have to install the software you want to host in that container after creation.
These scripts let you run a script that makes the container and also installs what you want to host within the container and does the setup.
I used their script to set up a home assistant vm, you run the script and it downloads the HaOS install media and does the install in the VM for you, preconfigured, and starts it so all I had to do was go access the web interface.
You could probably make $800 doing game dev too. Maybe not with only one game, but $800 with game dev hobby sounds better to me than $800 to be a warehouse associate for an unknown amount of time...