Did you set up your emulator? The first two steps to do when you start using AM are:
- configure your emulator(s) using the Emulators entry, there you can configure MAME or other emulators with executable paths, roms etc. You can also use this part to scrape metadata but for starters you can rely on local data. don't forget to regenerate the roms list...
- configure a display, using the Displays menu entry. Without a display you won't be able to see your game lists even if you have configured the emulator correctly