I only see one stepper driver plugged in. I guess that's because you're just testing with one motor to start with?
How do you know that your motor is connected correctly to the RAMPS? When it's powered on but not moving, can you turn it by hand? What are the voltages on each of the wires to the motor?
How do you know that your motor is connected correctly to the RAMPS? When it's powered on but not moving, can you turn it by hand? What are the voltages on each of the wires to the motor?