Just an off the the cuff response. I don't have a TC, so no direct knowledge of your situation.
Likely whatever factory wiring that is in place was routed during construction, and will likely be difficult or impossible to follow now that everything's put together.
If you have a free fuse circuit on your DC panel, route the cabling in whatever manner is most accessible for you, and will keep the cable out of your way.
For 12v, I recommend Ancor duplex marine cable. 12 ga for a 20 amp circuit, 10 ga for a 30 amp circuit:
WestmarineIt's very nice cable, very supple and the strands are all tinned to resist corrosion. Genuine Dealz will likely have it for less, they didn't pop up right away when I searched.
Home Depot carries a selection of easy to use plastic surface-mount wire track, that may be of interest. Wiremold brand I believe.
2013 KZ Sportsmen Classic 200, 20 ft TT
2020 RAM 1500, 5.7 4x4, 8 speed