Where do I fill the transmission fluid at and could that affect the engine to over heat if its low?

Fill the trans through the dip stick tube. As far as overheating, that wouldn't cause it. Check the thermostat, check to make sure the radiator is clean and not plugging.

Just to add to this one most of the overheating on those cars is caused by a bad coolant temp sensor and possible corroded connector or a bad cooling fan motor. Does the cooling fan come on at about 3/4 on the temp gauge?If not there are two coolant temp sensors on that engine screwed into the head below where the upper radiator hose goes onto the head. Unplug the the bottom sensor with two wires going to it a yellow wire and and black wire then start the car the cooling fan should turn on. If it does then replace the bottom coolant temp sensor. The new sensor should have a brown connector where the coolant temp sensor connector goes on. Also inspect the coolant temp sensor wire harness connector the terminals should be silver if there blue or green replace the connecotor also. Let me know what you find.

Yes the fan kicks on when it should.

So the fan comes on at 3/4 on the temp gauge?Also when it overheats what is the temp gauge reading?When the fan comes on is there lots of air being pulled thru the radiator?Because I have seen bags sand fur debris clogging the radiator and ac condensor causing the engine to run hot.