Your vehicle has an automatic transmission shift lock control system which locks the shift lever in PARK when the ignition is the LOCK position. You have to fully apply your regular brakes before you can shift from PARK (P) when the ignition is in RUN. See Automatic Transmission Operation .
If you cannot shift out of PARK (P), ease pressure on the shift lever and push the shift lever all the way up into PARK (P) as you maintain brake application. Then, move the shift lever into the gear you want.
If you ever hold the brake pedal down but still can't shift out of PARK (P), try this: