I would like to now if the lines on a ac unit are the same as a car, is one warm and the other cold,and if so, if they arenot is that because of low freon

They are not the same, but yes one is warmer and the other is cold, but because they are not doesn`t mean its low on freon

The principle is the same: one is suction and one discharge with one cold and one warm. One possibility is you could be low on refrigerant, but that is not the only possibility.

Compressor could not be running, indoor/outdoor coils could be dirty, filter could be clogged... the list goes on and on. Can you provide any more info?