So, I've never used Hammer before. All I want to do is add autosaving and change the music for my test chambers... How would I go about doing this? Doesn't seem like it'd be that complicated...

Maybe later I'll look into how to do more complex things with Hammer, but for now this is all I really want to do with it.

Well you will need to learn the basics of hammer, Start here r-IblzeE-4MAs for changing the music you will need a "ambient_generic" and as for saving you will need a "logic_autosave" But you should watch the video for the basics. Hope that helped.