Hey nate–don’t get frustrated, it just takes some patience.
Totally worthwhile–my kids, wife, and I spent practically all of Sunday enjoying old Sega, NES, SNES games, what a blast!

If you’re totally new to Linux command line just take it slow, read some tutorials on the basics.

Easiest way to get set up: have the RPi attached to the XBox adapter, a keyboard and your TV. Sit on your couch with your XBox controller and a laptop. Connect to the RPi with SSH.

Now, you have the RPi visible on TV and on your SSH session; you can do all the Linux command-line stuff in the SSH, you can push files and ROM’s to it from your laptop via a network share, and you can fool with the controller and keyboard.

Don’t be afraid to re-image the RPi’s SD card if you get too fubared; start fresh. I re-imaged once after I’d gotten really close but still wasn’t working.

And above all, follow the instructions in:
https://github.com/retropie/RetroPie-Setup/wiki/Setting-up-the-XBox360-controller

After getting the initial setup…that is, writing the 2.3 image to the SD card, doing “raspi-config” to expand the partition, and installing the XBox driver….do method 3 of the above.

I’m working on getting MAME going now; none of my classic arcade game ROM’s work :(