There is no better way to learn electronics and 3D printing than building your own things. Adafruit has published a guide that shows you how to build a Virtual Pet Cube. This cute guy has a eye that responds to taps and vibrations. It can show emotions, play tones, and more.
You are going to need a 1.2″ LED matrix, vibration sensor switch, buzzer, IR LED and receiver, Adafruit Pro Trinket, and a few other parts to get started. More information is available here.