How do I wire a motor driver power supply?
Vcc is the logic supply, i.e it powers the chip. VMOT is the motor voltage. the chip has two H-bridge drivers that basically attach VMOT across the motor in either reverse or forward polarity. Both of these need to be powered. They give you two so you can use a higher voltage on VMOT which may be required by the motors.

Make sure you don't exceed the voltage specs:

Recommended motor voltage (VMOT): 4.5 – 13.5 V
Logic voltage (VCC): 2.7 – 5.5 V

If you put 5V on both Vcc and Vmot, they should be powered adequately.

There may be additional issues with your other wiring and code, but, I won't address them until you fix your power problem is resolved and we can be sure there are other issues.

ADDED:

Here is the schematic of the breakout board, this seems to show that you still need to attempt powering both.



Vcc and Vmot are NOT connected on this board, have you tried using a multimeter to measure if they are on yours?