This is for LMDE6 out of the box experience. It should look similiar to this.
Next navigate to Software Sources. Refer to image below.

Open Software Sources. Type Steam in the search box and it should be the first one.
Steam also automaticaly downloads the other programs needed. See the green checkmarks?
LOGIN to Steam before doing anything else.

Open Software Sources. Go to the Flat pak tab and click.
Type In Proton Plus.
Then in the search box type Proton Plus and install the flatpak.

This is another Flat Pak so again navigate to Software Sources, Flat Paks and type in LACT.

Most people understand why installing steam is necessary ( you are here after-all) so that doesn't need an explanation. Proton Plus is another matter. This program allows you to pick which compatibility API you may want to use or need for Steam. Glorious egg roll, Sarek and Sarek a-sync (for my RX590 and Polaris in general), Cachey-OS are all in one application. When you download the API it is automatically installed in Steam and will be ready after you restart Steam.
LACT is nearly as good as Afterburner for fan control and overclocking.
Overclocking isn't as stable as Afterburner (within 5-10 mhz) but undervolting is spot on.
fan control is flawless.
LACT provides information about your graphic card like tech Power up.

I am hoping that with the new Steam eco-system, Steam OS will be released to the public. I want these programs to work well on Linux (and SteamOS) so I can completely ditch Windows. I recognize how for Linux gaming has come in just the last few years. I find that LMDE6 with the above programs is a viable option for novice Linux users and I hope someone finds this guide helpful.