By the end of this complete course, you will have a strong Arduino foundation and you will be able to start any custom Arduino project that you want.
From O'Reilly

Learn basic elements used to build circuits, and find out what happens when elements are connected together into a circuit.

This beginner-level course explains basic electronics theory and basic electronic components; shows you how to use the Raspberry Pi single board computer and the Arduino microcontroller/programming environment; and then demonstrates how you interface the Arduino/Raspberry Pi combo to a broad array of things (e.g., sensors, LEDs, power supplies, integrated circuits, amplifiers, RF device, etc.) that will allow your inventions to sense things, make sounds, emanate light, send out radio waves, and more.
From O'Reilly