https://www.raspberrypi.org/
Raspberry Pi for Beginners: https://projects.raspberrypi.org/en/pathways/raspberry-pi-beginners
Raspberry Pi Projects: https://projects.raspberrypi.org/en
gpiozero - simplest library for physical computing (good for beginners -- start with this!)
use the documentation linked above to help you solve problems.
for example, find all the methods for the LED class here.
find all the methods for the Button class here.
RPi.GPIO - probably the most popular library for physical computing (but less beginner-friendly)Â