One of my highschool friends thought it would be fun to work together on an electronics project, to build a 8-bit TTL-based computer from scratch. I had no experience or knowledge of electronics, but it did sound like fun so I agreed. I prepared before his visit, buying a cheap multimeter, some cheap breadboards, and a Raspberry Pi. He supplied all of the parts we would use for that first visit.
My goal for that first session was to get a grasp of the basics. To that end, we built the RPi interface, using a 74ALS245 transceiver, 74LS244 line drivers, and 74LS373 octal latches. Our plan was to have 16-bit addressing, so the RPi would have to load half of the address registers at a time, with the two 74LS374s acting as XL, and XH. I was learning the basics of electronic circuitry, learning the 7400 series family of TTL logic ICs, and learning python at the same time... and none of it really stuck with me.
I went to mouser to order my own set of components, including jumper wires and a variety of TTL logic. I also ordered a 6502, 6522, some SRAM, and an 8k EEPROM. This started a process where I would place a $100 mouser order each year, to prepare for us working together on this project.