So what specifically is your question about it? On my buddy’s Lund we installed a 2 bank onboard charger in the port side area at the walk thru and installed a 120v plug up in the bow.
At the batteries, positive lead from the trolling motor to positive post on battery A and negative lead from motor to negative post on battery B. Run a short jumper cable between negative post of battery A and positive post of battery B.
Make measurements at the box, I remember it being very tight so know what you can fit before buying too big of batteries.