Make a PiBot do some stuff! Excitement! Adventure!
Intro to gpio: https://www.raspberrypi.org/documentation/usage/gpio/
More info: https://pinout.xyz/
If videos are more your thing: https://youtu.be/41IO4Qe5Jzw
Tutorial for python and GPIO: https://learn.sparkfun.com/tutorials/raspberry-gpio/python-rpigpio-api
And another: https://makezine.com/projects/tutorial-raspberry-pi-gpio-pins-and-python/
Python module possibility: https://sourceforge.net/p/raspberry-gpio-python/wiki/Examples/
Intro: http://hertaville.com/introduction-to-accessing-the-raspberry-pis-gpio-in-c.html
C++ GPIO interface library: http://wiringpi.com/
Pi4J: http://pi4j.com/