It depends on how low you want to start. I started with microcontrollers from the beginning because the stuff I wanted to do from the beginning was way out of bounds what hard-wiring the circuit to behave one way could do (pretty easy to exceed). If you want to learn the absolute basics about resistors and stuff you could start low, but if you already do you shouldn't really need to since you can't do too much.
Well what you want (in it's absolute barest, simplest form) is for the right (or left) motor to stop when the right sensor on the robot says nothing is in front of it. This should give you wall-following maze-travelling behaviour. So connect the left motor to the battery. Then connect the right motor to the battery in series with a switch (or some kind of sensor-switch) that disconnects/opens when it detects nothing in front of it. Of coure, this way has many problems with it the first of which is finding a switch-type thing that will open when nothing is detected in front of it, not to mention it is blind in front.