My air conditioner blows cool air (not cold) when I am driving, and when I am stopped, it is warm air. I had to replace the sensor last year. Could it be that again, or something else?
Get a thermometer and check the air temperature when you are stopped and when you are moving. Do this after the car has a chance to cool down. Let us know what the cabin air temperature is and the air temperature as it blows out of the register on the dash board. Warm air often means that your refrigerant is low. The temperature difference helps determine this.
You just need to take it to an automotive AC shop.