Adding Kicker Sub to factory unit

Hi! I've been searching around on the site. I've found some very specific information on people's install and was looking for the same type of info on mine. I'm by no means an expert on this stuff but I've recently replaced a radio on my other car (as well as added a backup camera). That one was an older civic so tons of youtube videos and pictures. I bought a kit to help pry panels off and comfortable doing basic wiring. The difference here is that I'm not just buying a converter kit for the wiring and plicing things together and plugging in the new where the old used to be. My Trailblazer doesn't have the subwoofer in the spare tire area that I've seen others do. I'll try to provide as much info as I can - let me know if I need to check out more to help provide more! Appreciate any help, links to guided videos or pictures. I will say I've looked at the attached pdf (thank you"Thecrowtv"!) but still not sure exactly which wire to splice by wires into. Thanks!

Car - 2022 Trailblazer FWD LT
Convenience package - 8" touchscreen, if that matters. Believe the rest of the speakers and everything is stock - don't believe it is with Bose - if there is a way to confirm happy to look.

Looking to add under the driver seat -
KICKER 11HS8 8" 150W Hideaway Car Audio Powered Subwoofer Sub Enclosure HS8

I also bought this in prep which I believe I need?
Kicker KISL 2-Channel K-Series Speaker Cable to RCA Adapter

My main 2 questions are:
Where do I specifically connect the wires I bought with what is stock in the car?
I understand I need to run power up to the battery, how do I pull those wires from the battery to the interior down under the drive seat? Maybe easier than I'm thinking you just shove it through but pictures on where would be helpful!