Drove into the Walgreen's parking lot, made several low speed turns to arrive at the west side of the building. Pulled into an empty parking space. Entered parking space at very low rate of speed and proceeded to brake to a full stop. Moved shift lever with the intent to move transmission from Drive to Park and despite my foot still being on the brake, the car suddenly lurched forward, drove over the curb and sidewalk, crossed sidewalk and hit the side of the store (a brick wall). Car bounced back to a midpoint of the sidewalk. Engine was still running but car came to a full stop. I turned off the engine. Two Walgreen employees came out to see if I was OK (they heard the impact). I told them I was but later my chest hurt and I found a bruise suggesting impact with the steering wheel. Entire front of car is damaged. There were no warning notifications from the car (no parking or forward collision warnings). My right foot never left the brake pedal. The "unexpected acceleration" lunge forward occurred with the attempted shift of the transmission from Drive to Park. The transmission ended up being in Neutral when the car finally stopped moving. Floor mat was in the normal position, secured by the built-in pins, had not shifted and was not near the brake or accelerator (gas) pedal. Cruise control was not turned on. This was a routine trip to a local store.