I need help with two things

I need help with two things

  1. At the moment i am working with numark mixtrack quad, usually this comes packaged with virtual dj, instead i changed to traktor, i got a custom mapping for the controller but i came across a problem. When i connect my headphones into the controller no sound is emitted in the headphones even if i cue the track.

  2. how do i create a tense build up in a track that would lead to a sick drop.