Playnite: A tool unrelated to this particular setup, but worth noting. It's an open source beautiful game library manager for your PC.
Nucleus Coop: This is the software that opens multiple instances of your game and runs it on one machine for the "couch" part of couch co-op
DS4Windows: Install this app if you want to use your PS4 / PS5 controllers on your Windows computer.
Skyrim is a vast and open world with hundreds of hours of enjoyment to explore and create adventures, which is exactly why you shouldn't be alone in this adventure. Let's setup multiplayer as well as some quality improvements to bring it into the year 2021.
To get multiplayer working, the best solution is "Skyrim Together".