I wanted to get into robotics as a way to get up to speed on neural nets and reinforcement learning. I found the Lego EV3 kits to have a good mix of sensors motors and supporting parts. The EV3 bricks run Linux, there's a distribution for them called ev3dev, and they'll even run ipython notebooks.
I'm now looking at getting a BrickPy for it as the EV3 brick doesn't do FP, so not good for NN's.