I WENT TO LARGE GROCERY STORE AND PULLED INTO THE PARKING SPOT AND PARKED IN AN EMPTY SPOT NEXT TO ANOTHER CAR. AS SOON AS I PARKED, MY CAR TESLA MODEL 3 SUDDENLY ACCELERATED AT A HIGH SPEED AND SHARPLY TURNED RIGHT ON ITS OWN WITHOUT ANY PROMPTING. IT WENT FULLY ON TOP OF THE PLANT BEDS AND HIT TWO OTHER CARS FROM THE FRONT. LUCKILY, I SLAMMED ON THE BRAKES IN TIME AFTER I PROCESSED THIS TERRIFYING OCCURRENCE AND PREVENTED THE CAR FROM HITTING ANY PEDESTRIAN. WEATHER CONDITIONS WERE NORMAL FOR THE AREA WITH SOME LIGHT RAIN. I HAD NOT USED/ENGAGED ANY OF THE TESLA AUTOMATIC DRIVING FEATURES DURING MY TRIP AND PARKING.