Many automatic transmission cars have a shift lock detent to prevent the vehicle being taken out of Park until the brake pedal is depressed with the ignition key on. A signal goes from the brake light switch to the shift lock module. Check that the brake lights work first. Most vehicles have a way to get the vehicle out of Park in case the battery has gone dead or the shift lock detent solenoid or module fails. I'll send you an article about the shift lock to your email address this question was sent from. Check fuse #6 (5 Amp) and fuse # 13 (15 Amp) in the fuse box.