You'll learn just keep asking the questions. Like I said go get a manual for your truck, it will pretty much give a detailed description on how to completely tare down and rebuild your truck. That's the 1st thing I do when I buy a new well-used car.
If you pull the wires and turn the key just be careful you can get a good shock real easy.
I am going to suggest that if you know any mechanics see if they will help you work on your truck on Saturdays or something like that. That's kinda what I did in high school. He got to the point where I'd pull in he'd say what'd you break, I'd tell him and he'd say you know where the tools are let me know if ya need me. That's where I really learned what I was doing on a truck.
Blood Sweat & Gears
I got your JEEP thing It burns when I pee