Oh I forgot to mention if you ever run into a situation where you aren't sure how compatible a game is on the deck check out ProtonDB. They have a comprehensive list of games that either work, don't work, or need some sort of method to get them to work. They also have users who post the how-to.

Some games have a tendency to need work arounds to play on the deck but I found that if it's also on GeForce Now you should play it through there if you have the dock and a wired connection. Destiny 2 is a perfect example. Congrats and enjoy!!!

Retroarch off of the Steam Store is an amazing emulation powerhouse! It's got a huge library of retro consoles aka cores.