First check out the official tutorial:
https://www.dexterindustries.com/BrickPi/brickpi-tutorials-documentation/program-it/python/brickpi-python-idle/
It won’t show you everything. But when you complete it you’ll know basic stuff like moving servos and getting input. I then suggest looking at the example code. That can be found on github. Or in the BrickPi/Software/BrickPi_Python/Sensor_Examples folder. You should be able to figure out how to do anything from there.
You can also view the brickpi module docs by importing it into python import brickpi and then help(brickpi) If you still can’t figure out what you need to knos there is of course the forums.