There are many ways to learning this. One reasonably quick way is to get one of the training kits made by Microchip. I've tried both the Low Parts Count Demo Board and the PICDEM Lab board. Both are excellent and will teach you what you need to know about getting started programming microcontrollers. The PICDEM Lab board is a better choice in my mind because it's more versatile for performing other experiments down the road. If you work through the tutorials, you'll learn the basics of analog in, digital I/O, switch debouncing, interrupts, ISRs, etc.
There are also USB kits that connect to your Windows/Linux/Mac machine and let you do stuff with high level languages; there are often bindings to your favorite language.
Enter to Win a Raspberry Pi 4 built into a compact keyboard! We'll be selecting the winner at the end of this month - click here for more information.
