Sidechain is where the synths duck under the drums. This is done the easiest with the synths Centroid going into the input of a compressor, and a machinist going into the sidechain input (you will need another drum machine for this, as the sidechain drums will be muted) You can probably find a sidechain preset for the compressor.
Two things that you NEED in EVERY song that you EVER make are sub-bass and sidechain. Sub-bass is a mono, no-release, no delay, low sine wave. (I'm talking C1 to C2 here) Make sure it goes with the melody or the bassline (preferably the bassline).