Reply to newbie. which cables do i need/ setup S4 + audio 2 dj

Hello

i bought the traktor S4 + audio 2DJ from NI
which cable do i need to connect the S4 to the audio 2 dj to use on output A for master and output B for headphones.
i don t really get how to set up this...
do i have to plug the heaphones to the audio 2 dj or to the S4 ?

main question is : how do i setup the S4 + headphones with an Audio 2 DJ from NI and my computer (no ampli, only computer speakers)

really stupid questions sorry for that.