[RyanW]

If you want to identify movement you probably want some combination of gyro, accelerometer, and/or encoder sensors. I don't have much experience with any of these, but:
The gyro should tell you how your robot is turning
The accelerometer should be able to tell you acceleration in two directions, which you can integrate to get speed and again to get position (it can also be useful for other code, like traction control)
Encoder sensors can be mounted with wheels to tell you exactly how much they're spinning, and you can get distance by counting the ticks and multiplying by a constant factor. Of course, if your wheels are slipping your encoder count won't match your distance traveled...

If you just want your robot to move, all you need to do is drive the motors like you would in the teleoperated period (although not from a joystick, since you can't read from those during autonomous).