When I put the key in and hold the steering wheel it won't unlock and my key won't turn

try pulling the steering wheel slightly to one side and turning the key to unlock the steering wheel

The list of possible causes includes the key, the lock cylinder, the steering wheel lock, and other things.
Have you tried another key ?

push your foot on the brake pedal and try to put it into park, then turn steering wheel at same time as you try to turn key

Usually a sign the tumblers in the lock cylinder have worn out or jammed.
You may have to get the lock cylinder drilled out and replaced.

I'm assuming you mean your key wont turn in the ignition. first off check to make sure the car is in park. then what you gotta do is put in the key and put a little pressure as if turning but dont turn too hard, then even though the steering wheel is locked you will have to try to move it a little, if you parked with your tires turned then you will want to try to turn the wheel in the same direction, (even locked you should be able to move it about a half inch) you will have to turn the wheel hard but it should move enough to allow the key to turn, you may have to jiggle the key a little in the ignition but it should eventually turn, just remember not to try turning the key too hard, the extra force wont make it go but can cause the key to break. this tends to happen when you turn the car off andthe steering wheel gets locked if the wheels are turned hard in either direction. also if multiple attempts at this still dont work, try taking the key out and turning it over and trying again. Even though both sides of the key are identicle, because of wear on the key and the ignition, sometimes when the wheel locks the ignition, it will only turn if the key is put in a certain way. Hope this helps, good luck

If nothing is holding it like the steering wheel or shifter, you may need a new lock cylinder. Did you try a spare key ?

You may want to try to slightly push / pull your vehicle to take weight / tension off the transmission, which in turn will allow you to turn the steering wheel enough to see if the ignition switch can be turned.

To fix your problem, you have to turn the steering wheel either to the left or right as much as you can, then try to turn the key in the ignition. When the steering wheel locks, the key won't turn. By manually holding the steering wheel out of the lock position, the key will turn again and you're steering column will be back to normal.

You may have to use a little muscle here. When this happens, turning you steering wheel to the left usually will release the ignition lock cylinder so tha you can turn the key. Make sure you hold the steering wheel once you have turned it. Keep in mind, it won't turn very far. One side you turn to will feel like it hit something solid, the other side you turn to will be the unlock side.

So
Turn steering wheel and hold until you are able to turn the key. It will take a bit of effort on your part, but that should get it back going.

Grand Prix will not unlock put the key in and it won't turn at all it seems to be locked up What can we do