Linux Mint can be used almost entirely from GUI, so you should be able to install both Steam and Heroic through the software “store”.
Here are two guides specific to installing Steam on Linux Mint.
I don’t know what games you are playing, and I only used Mint for a short time before moving to other diatros, but I remember it being pretty plug-and-play for most things. I admit I was mostly playing through Steam and a few applications through Lutris (mostly FFXIV), using a Wine wrapper to use the official launcher.
For Steam, the Steam launcher will handle most of the game-specific launchers for you. For Lutris, make sure you open Lutris and update it after installing it and before trying to add any games to it. I don’t have any experience with Heroic (or with Windows version of Epic Launcher either).
That kind of seems like that is exactly what these are. The specs are still sort of terrible, though, but pricing isn’t too far off for what is advertised in them.