how do you make a mix of songs on garageband

What is your GarageBand version?

With GarageBand 10.0 do the following:

• Collect the songs you want to mix in a folder on your Desktop or an album in iTunes.
• Create a project with just one audio track.
• Drag the audio files in the right order from the Media Browser > Audio tab to the audio track (or from the folder on your desktop).
• Use the volume automation curve on the audio track to adjust the volume to fade the songs in and out.
• Use the share menu to bounce the song to your disk or to iTunes.

It seems, without a master track, if you wanted to fade out, you would need to fade each track individually. Right?

And, what kind of file are we creating?