Circuit Playground Developer Edition Kit

Circuit playground classic is the best way to practice programming on hardware with no soldering or sewing required. The classic version contains ATmega32u4 and is designed to work with Arduino IDE and code.org CS Discoveries only. It also comes with Firmata already programmed in so you can use it with code.org Discoveries without any preparation or updates.
Circuit Playground has built-in USB support so you can plug it in and it just shows up. All you need is a Micro-B data/sync USB cable (not included).