Arduino is a wonderful platform for learning about electronics and coding. The Cherokey Robot Kit comes with everything you need to build a simple Arduino robot with obstacle avoidance and remote control. It uses a L298P motor driver chip to drive 2 x 6-12V DC motors.
This robot has an ultrasonic sensor with a detection range of 4cm to 3m. It has max payload capacity of 500g. Its body is made of an aluminum alloy. More information is available here.