OK. DC circuits are intimidating you, but you admitted it. I'm not sure at what level, so forgive me if I assume that they REALLY intimidate you.
We recently faced helping high school
students who are hands on learners understand basic DC circuits. We ended up giving the class (traded them for a 1946 unused sextant!) these kid's circuit kits:
I found them fun, and I survived (barely) Electrical Engineering 101. My wife (chemist) enjoyed them as well.
It may seem pedantic, but people coming along now do not get the experience with automobile 12 VDC circuits that we did growing up, and the kits take them through 100 circuits bit by bit, and if it will help you, please don't be embarrassed by the "age 8 to 12."
Do you have a digital multimeter? You need one if you don't, they're cheap
, and you can start at the battery
and trace a circuit from there to (say) the nav lights and back to the battery
. Draw it as you go.
Best wishes on it.