I was reading your post and all of the advice that you are getting is good. I just wanted to add something that has helped me out in the past. When I was in shop class back in high school I was real good at wrenching but electrical issues always intimidated me. My shop teacher explained it like this,
Electricity and water act the same in many ways. They always try to find ground. Water runs down hill and electricity always looks for the ground.
Electrical wires are basically the same as pipes for water, the more electricity that you are flowing, the bigger the cable you need to do it without problems.
Water volume is similar to voltage, water pressure is similar to amperage.
They both take the path of least resistance. If water can take a diversion that is easier it will. If a cable has a bare wire the electricity will go that route instead of going towards (and powering) a light or motor for instance. I think of this as a garden hose that has a hole, the water will run out of the hole instead of powering an oscillating sprinkler for example. A short to ground is like a water leak.
Switches are the same as valves, they both allow something to pass or block its travel. They both can get stuck open or closed also.
Fuses are similar to a switch in the way they operate but they only do it one time. Once a fuse burns and stops the flow, it is garbage and needs to be replaced. Relays can reset, (automatically or manually)
Batteries are storage tanks, some are large and some are smaller.
Alternators are like water pumps in the sense that they produce output, but they must have a supply to start with.
When you are trying to troubleshoot electrical you always start at the beginning of the flowchart to eliminate the problem. these flowcharts are made by smart people and there is a reason to check each thing in its order. Skipping a step that seems redundant can cost a lot of time and money.
Electrical schematics are intimidating when you first look at them. I look at them the same way that I would look at a plan for an in ground sprinkler system. The electricity will start at one part and continue to its destination unless something is wrong. This is why it is important to follow the flowchart.
Water and electricity always follow the rules. You may encounter a new issue but the way that the electricity reacts to it will always be the same unless something changes.
Some of these explanations are simplified and I don't want to insult anyone's intelligence. I still use this method of thinking after many years of Ford and Chrysler driveability factory training. Each time I need to diagnose something I always start at the beginning and I don't assume anything. Always verify something instead of writing it off as unimportant.