Overheated now wont start

Try turning the key to the run position without starting the car. See if it wil now give up the park position into neutral. If so, start the car, put it in drive and go. I have experienced this same problem with Ford Crown Vic sedans.
Jim K,Chicago

Could be several things from radiator ,hoses,water pump, FREEZE PLUGS ,cracked head or block. You need to find out where the coolant is coming from to determine it.
If the car was hot and you poured fluid in it the block,head or head gasket could crack. If it was cold and you just had watr in it the block could crack or freeze plugs could have came out.

Have you had your transmission fluid and filter changed? Sounds like the fluid may have lost its viscostity

Sounds bad. Where is the transmission fluid going? I hope it's a leak and not getting into your antifreeze. DO NOT just run water.
Of course,change oil and filter to a good 10W30 synthetic to resist the heat (Pennzoil Platinum is good.
Now as to overheating.Change your thermostat(you need a thermostat in there) to make sure it isn't a problem.
Now as far as the leak...........you could pull the trans and fix the freeze plug(which is probably leaking) OR if it were mine and I wanted to postpone the expensive repair, I'd put a can of the liquid copper stop-leak in it(BAR'S LEAKS, I believe is the brand),then when it seals,drain the coolant out and after it cools, add pure concentrated antifreeze to achieve a 60/40 ratio. When you test your antifreeze it should show at least 45 below zero.
Do you think your radiator is plugged up? Could the fins be blocked with dirt or debris in front?
If you were running just water,it was probably boiling on you and that can ruin your engine because of air bubbles,voids.
If it IS a head gasket,you should see steady bubbles coming up the neck of the radiator,or the expansion tank even before it warms up.
don-ohio

Check the transmission linkage cable that runs from the steering column under the dash to the trans under the car. make sure that the cable is not damaged and that all connections are tight.

oil change every 5000 miles, tire rotation every 10 to 15000, air filters at 15,000 or as needed, fuel filters and auto trans fluid every 30,000.

a late opener will make it run cooler as it cools the radiator for longer

need more info it could be fuel pump as well as the transmission make sure trans. fluid is on the right level

Before you get into this involved job I have a few suggestions. First is the pump leaking causing the system to lose coolant. Grab the fan and try to move it from side to side to see if there is play. Next when was the last time the thermostat was changed out. The thermostat can be stuck in a way as to restrict water flow. Another cause of over heating is a clogged radiator. Older cars can have a slug build up in the radiator core causing a significant cooling lose.
Water pumps on a Crown Vic is located on the front of the engine behind the fan. You should really get a service manual as there are a lot of steps in this job that must be done correctly to avoid future problems.
You start by draining the entire cooling system by opening up the drain plug on the bottom of the radiator. This antifreeze must be disposed of properly by taking it to a repair shop for pick up. Next remove the fan guard followed by disconnecting all the belts. Some people remove the radiator to gain working room. before removing the radiator disconnect the lower hose and the upper hose to the engine. The transmission oil cooling lines are next. Now remove all the bolts holding the radiator in place. As you can see this is not a job for a novas. If you are not mechanically inclined this could be a nightmare of a job.

First things first...check your fluids! Automatic trans. fluid : park brake applied, engine running in park, check dip stick. Fluid should be at full mark and brite red with no smell of burn. Report back with fluid condtions, a little leg work goes a long ways...