Pulled into parking lot and went into a store. Upon leaving I noticed the vehicle would not back up when placed into reverse gear. The engine would rev but, no movement. I pushed the vehicle backwards and then restarted it. The vehicle would move forward. I stopped and attempted to try the reverse gear a few more times with no luck. As I started driving on the main roadway toward the GM dealership, the vehicle upshifted once and then displayed a warning along with e check engine light. Once at the dealership, they scanned the vehicle and confirmed a transmission issue. The vehicle never showed any symptoms prior to the failure.