Please, there are so many options out there for you that are probably better suited for your needs than SteamOS will eventually be. You must have seen this repeated over and over again. Waiting for SteamOS on desktop makes no sense. Just go ahead and install Linux now. Any distro, switching is easy if you're not happy.
If you want a distro that is good for gaming on desktop I'd still recommend Nobara for now since it is based on fedora and modified by the person behind the glorious eggroll version of proton.
The existing guides have not yet caught up with the paradigm shift of atomic distros.
When I say it's newbie friendly, it's because the base system is read-only (only /etc and /var are writable), and updates are only applied if all transactions are successful.
This paradigm shift requires people to install flatpak applications and command-line applications in distrobox containers.