I had a similar problem while out of town so I know how frustrating it can be. The bad case scenerio you blew your transmission & the gears are locked. Few questions you should ask...
There is a plastic mechanism in the gear shift assembly. You need to take apart the top covers;chrome plastic piece, cover, etc. After that push the hot pink plastic tab in while shifting into gear....
The solution to your problem may be as simple as depressing the brake pedal to release the shift lever. If you're parked on a hill it could just be jammed. You'll need to release the pressure on the...
Check to see if the brake lights are working shift interlock and stop lights are a common circuit.
Try turning the key to 1st (unlock) position shift to neutral to start and then shift to Drive