Where did everybody learn how to build/work on computers?

I’ve always been interested in computers and I’ve always wanted to build one, I’m just unsure where to start.

I’ve never done anything like this before and I’m really worried that I’m gonna break something.

I tried taking a class at a local collage that was advertised as a beginner course. Despite being a “beginner” course, everybody else in it had several years experience.

Also, the day 1 assignment was: fully disassemble and rebuild a computer with no help or instruction, good luck!

I don’t understand, was I supposed to learn all this when I was a kid? Did I miss a day in 4th grade when this was covered?

I want to learn how to do this, but it’s feel like I’m getting gatekept every step of the way.