I have big plan with DIY robotics, but no experience. So I thought to begin with something simple and form there I can go bigger and bigger. So I checked my drawers and I built my very first robotic car.
After some hours my very first robocar waked. I call it RoboCar Zero (v1).
The 9V battery feeds the two stepper-motor drivers. The headless RPiZero is fed through a simple 5V voltage regulator + capacitors. I use 8 GPIO to control the stepper motors through a Python script. The body is a piece of wood and I used a lot of hot glue.
Because of the stepper motors it was very accurate, but also it was slow, weak, and it drained the buttery fast. So it had its limitation, but for my first robocar I was proud of it.
If you need more details write a comment and I'm ready to help.