Key will not turn

First thing would be to try a second key. Keys can wear enough that they no longer work. Also, try pushing the shift lever toward the park position as you try to move the key in case the park lock jammed it.

If neither key nor holding the shifter works then it is likely to be a bad switch cylinder. The problem with that is that you need to be able to rotate the key to install the new cylinder easily. As you cannot it is a bit harder as you need to drill the release pin out to enable you to replace the current cylinder.

One step here that can save you a lot of hassle later would be to get the new cylinder coded to match your current existing keys. That way you do not need to carry extras to open the doors and trunk plus you do not need to have a dealer or locksmith reprogram the system to read the replacement keys.

To do that you disconnect the battery negative connection. Then you remove the upper steering wheel trim cover.
Then the instrument cluster trim panel and the cluster itself. (Pictures 1-3)
Now you remove the accessory trim panel the one around the radio and the center stack. To do that you use a thin screwdriver to remove the ignition switch bezel and then use a trim stick to pop the retainers that hold the trim in place free. Disconnect the electrical connectors at the top and rotate the trim and set it aside. (Picture 4)

Now you can get to the ignition switch bolts to remove it and drill out the lock cylinder. Remove the bolts and the electrical connections, Disconnect the park lock cable connection and remove the switch. Pictures 5 and 6)

Then follow the process below to drill out the retainer.

If the lock cylinder does not rotate or is seized, perform the following procedure:
12.1. Protect the immediate work area with suitable material such as clean shop towels or a clean fender cover.
12.2. Locate the surface for the ignition lock cylinder release button (2) on the plastic ignition switch housing and center punch a location (1) on the rib 9.5 mm (3/8 in) rearward, toward the key entry end, from the cylinder release button. (Picture 7)
12.3. Carefully drill a pilot hole through the plastic housing with an 1/8-inch drill bit.
12.4. Carefully drill a larger hole at the pilot location, and slightly into the ignition lock cylinder surface to break the release button retaining spring using a 9/32-inch drill bit.
12.5. Remove portions of the broken spring from the hole using a small suitable tool.
12.6. Grasp the ignition lock cylinder and remove the cylinder from the switch housing.
12.7. Remove any plastic flashing from the drilling operation, and using compressed air blow out the ignition switch assembly.

To install the new lock cylinder you reverse the process. You may need to put the back of the 9/32 drill into the hole to guide the release pin back into place.

Now that you have the new ignition together you need to program the system to accept the new keys. (If you had the new cylinder cut to fit your old keys this step can be skipped.) For this you need either a locksmith or dealer who can access the system to program in the new keys so the immobilizer circuit does not trigger.

It is possible you bumped the transmission park lock cable. You might try wiggling it where it is attached to the switch. It could have pulled the lock out of position.