can't hear anything. please help

So I just bought Cross (FINALLYYYYYY). I was ready as hell to fire everything up and hooked my MIDI controller (Numark Mixtrack Pro II btw). had the mapping. Everything's working like a charm except.... I CAN'T HEAR ANYTHING.
I don't have speakers but I do have headphones. I hooked them up to the headphone jack in the controller. i went to the Audio area in Preferences and I don't really know what to do about the Audio routing mode.
I have used Serato Intro a few times and didn't have any problems at all when it came to using headphones. Is it possible to use headphones without any speakers while Djing with Cross? Is it not working because I'm using a desktop instead of a laptop (this is my first time using a desktop for DJ software, rather than laptop)
can somebody guide me here?
I don't have speakers but I do have headphones. I hooked them up to the headphone jack in the controller. i went to the Audio area in Preferences and I don't really know what to do about the Audio routing mode.
I have used Serato Intro a few times and didn't have any problems at all when it came to using headphones. Is it possible to use headphones without any speakers while Djing with Cross? Is it not working because I'm using a desktop instead of a laptop (this is my first time using a desktop for DJ software, rather than laptop)
can somebody guide me here?