Can't say if your truck is pre-wired or not. My 1999 K3500 Chevy was NOT, despite ordering the trailering package. What I got was an extra blue wire in the harness for the trailer brake circuit and a brake light feed pigtail under the dash to trigger the brake controller. That's it. If I had not ordered the trailering package, I wouldn't even have gotten these wires.
Now my 1999 is the old body style. Your 2000 new body style, so I don't know if your truck is different or not, or if it has the trailering package or not. In any case, wiring the controller was trivial. Power, ground, trigger, and the brake output were all that was required. The brake output wire was factory routed to the back bumper, so that was easy to connect to the trailer plug. There was an under-hood junction block, so I connected the fused power wire to it.