2 times I thought car was in park and when I got out,the car was moving. The last time the door knocked me down and the car ran over my foot and ankle.

Sounds like the shifter cable is not attached or adjusted properly. Alex

Have a qualified mechanic check the transmission park mechanism .. IF the engine is cranking ok with shifter in park - obviously the shift linkage is telling the park neutral switch the transmission is actually in park .. Possible parking pawl damage inside the transmission .. This is a very serious problem .. Have it tested ASAP .. Use the parking brakes each time car is parked.. Be careful!