Arduino is a great starting point for electronics, and with a motor shield it can also be a nice tidy platform for robotics and mechatronics. Here is a design for a full-featured motor shield that will be able to power many simple to medium-complexity projects. Build the kit, and learn how to use it with these detailed instructions.
Spin two DC motors or step one bi-polar or uni-polar stepper with up to 1.2A per channel using the DRV8833. This motor driver chip is a nice alternative to the TB6612 driver. Like that chip, you get 2 full H-bridges, but this chip is better for low voltage uses (can run from 2.7V up to 10.8V motor power) and has built in current limiting capability. We set it up for 1A current limiting so you don't get more than 2A per chip, but you can also disable the current limiting, or change it to a different limit!
Here's a guide to quickly and easily adding exciting, colorful lighting effects to your props. Using the accelerometer, speaker, and NeoPixel LEDs built into the Circuit Playground, you can have sounds and lights for idle animations, along with two different effects triggered by waving and striking your foam sword, cosplay blaster, magic wand, and more.