We don't support 3rd party images, especially the ones loaded with ROMs. Note that selling preloaded RetroPie systems is against the project's license.
Use the image from retropie.org.uk/download to install RetroPie.
So no real explanation. I came home, scratched my head a few minutes, made sure my files were not set to read only, reinstalled the advmame packages, double checked my placements and linkage, rebooted the entire house... and it works now. Three randomly picked games loaded up. I need to map keys but yes, this is awesome.
In the attract mode motion blue & hyperpie, the sega and atari circuit board system display layouts pull from the advmame set, and it turned out to be one of the only sets I don't have, so this was awesome, not sure what all was wrong here.
From your post, I can kind of deduce that as you got this Retropie "kit" for Christmas, that it was purchased with the SD card pre-loaded. That type of image is not something that the devs here will support and you'd be better downloading the official image and following the initial setup guide on the wiki.