Take the mixer main outputs to the subwoofers, take the crossover / high pass outputs from the subwoofers to drive the power amp that is the running the main speakers.
Between the mixer and subwoofer inputs you may want to put at least an EQ in line.
Maybe find someone in your area who is decently good set up setting systems and running
sound to do some hands on training on the mixer and setting up the system.
EDIT…..I just double checked and those subs DO NOT have a high pass crossover output mode. So you will need to use an external crossover in some form to feed the power amp running the your passive main speakers.
What model power amp do you have, some include crossover functions.