Sounds like two issues here.
#1, it won't shift into, or out of park? Never seen one not shift into park, so that's why I ask. Many of these have issues where you can't get them out of park.
The door issue may be from a disconnected handle or broken handle, will need to remove the handle and possibly the door panel to inspect top see what is happening. If this is one of the read doors, then make sure the child safety lock is not on.