There is no better way to learn robotics than building and programming your own robots. The CKIT WobblyBot is a fun project from Adafruit that shows you how to build a CRICKIT based hopping robot. The robot has an anodized aluminum metal chassis. You are going to need 4 FS90R micro servos, mini geared pager motor with return spring, a Circuit Playground Express, and an Adafruit CRICKIT.
You can program such as robot with Python and C depending on the brain you pick for it. More info is available here.