Posts from How can I play Olden Era under Linux, and is it even possible? Auto-translated

sudo apt install steam

Next, in the program search, there was an icon for "Install Steam" or "Steam Installer" — I don't remember exactly, I didn't save a screenshot, but after clicking it, Steam downloaded and installed itself.

Everything just sort of worked on its own; the Nvidia drivers were already there. On a clean system, I think you'd need to install them yourself, or Steam will do it on its own (with AMD and Intel, the experience might differ, or with a non-Ubuntu distribution).

You can delete Windows now.