Here is another affordable robot that you can build and program to learn a thing or two about coding. The Kittenbot 12-in-1 micro:bit robot has all the parts you need to build 12 types of robots. It can be controlled with your phone or a microbit controller. You can program it with Makecode/MicroPython to learn through play.
This robot can be programmed to follow line, pick and move tiny items, and battle against other bots. You can find it on Banggood.