1987 Buick Century Leaks

I hit a rock last week and the other day I noticed the transmission wouldn't shift right. I checked the fluid level and added a quart of transmission fluid. I haven't used the car for a few days and when I went to use it it wouldn't shift right. I went about a mile and returned home. It was slipping real bad and wouldn't make it up a small hill on our driveway. I had to tow it with my Jeep to a level spot. We had to leave for 4 hours with our jeep and when we returned the radiator cap was too hot to check the fluid in it. When I had to tow it up the hill it was overheating so that is why I needed to check the water 1st. The temperature is about 100 degrees and the car is black and it was so hot I decided to wait to check anything.
I did check where the car was parked last night and there was a large oil leak there. I think that rock might have put a hole in the pan or something else. Later I will check the water again and after making sure it is ok I will start the car and let it warm up so I can check the transmission oil. I did check it when cold ant it shows some on the bottom of the dip stick. Should I put more in it before I start the car and get the engine hot or what?