when I step on the brakes and before I put it in park the vehicle trembles
Warped rotors maybe?
Silly question maybe but is the car moving when you apply the brakes? You say it trembles before you put it in park. That indicates (to my warped mind, anyway) that you’re sitting still, at least sometimes, when the problem happens. If that’s the case, you probably have a vacuum leak, my guess would be from a bad brake booster.
I have a feeling the vehicle is already stopped when you are stepping on the brake to put it in park, am I correct?
You and I seem to be on the same page.
Me too, like when the car is in drive at a stop its vibrating. Makes me think bad engine or transmission mounts.