I built my first drone in 2015
When I was 10, I fell in love with a small youtube channel called FliteTest. It was led by Josh Bixler and Josh Scott. They focused on planes, drones, and the basics of radio-controlled flight. They came out with their first starter planes, essentially a piece of foamboard cut in a shape with some vertical surfaces. They were called the FT Flyer and FT Nutball. You could scratch build them, or buy a pre-cut kit from their store. They then started to release more and more complicated builds, including models of warplanes and gliders all made from dollar-tree foamboard. Then, they started getting into drones. They sold a tricopter, then a kit where you could choose 4, 6, or 8 motors, and finally the FT Versacopter. It was a a PCB integrated into a piece of plastic (or some similar material). There were two carbon arms with motor mounts on the end. Looking back, it wasn't much. But for the time, it was possibly the most accessible drone you could build. They had detailed guides and parts to make everything relatively easy to understand. The channel has since grown to almost 2 million subscribers. You unfortunately won't see Josh Scott around anywhere, though. He stopped going on camera regularly years ago.
When I was 12, I decided I'd like to build a Versacopter. Below is a picture I took back then of all the components you'd need (plus a few helpful extras).
I had always been interested in electronics projects, so I had some experience soldering. This was where I really learned what I was doing, though.
This is the only picture I have of the build process. Pictured is the VTX (video transmitter, middle-left ET200), the wires going into the receiver/control board combo, and the motors attached to each arm.
This is the (mostly) finished product. It lacks the FPV camera (a smaller, low-resolution, and low-latency camera used for navigation). Notice the small pieces of rubber beneath the Gopro to assist in stopping vibrations. It had 6-inch propellers, bigger than most builds nowadays. The standard now is 5-inch. The video antenna is the dome at the rear, and the control link antennas stick up above the frame. It carried a 2000mah 3s battery, usually the size used for small to medium-sized planes. I actually still have and use that battery for other purposes. The quad was quite large overall, made for durability and ease of building rather than to be compact.
I might not have build videos, but I do have videos of me flying it in my backyard. Please excuse the dirt, we let the lawn die because we didn't want to waste water during the 2011-2015 drought for environmental reasons. It came back next year.