Have a 2001 Tahoe 4x4. Can't move the key either way, can't get shift lever out of park and steering wheel is not locked in place. Key goes in and out fine, lockout protection feature works fine, as far as I can tell, electrical seems fine.

With the key out, visually inpect the key slot for any contamination or foreign objects. Spray a small amount of lubricant inside (graphite is best) and tap lightly on the lock cylinder while moving the key in and out. You may need a new lock cylinder, but in case it is just a stick pin this might free it up.

Try to rock the vehicle forward and backward while trying to turn the key. The lock may have got jammed/stuck prematurely. Your key should have not been released. Also check the shift lever after wards if the key will turn. The parking pall will not release if the vehicle weight is pressing against it, so you will have to rock the vehicle again.