You may be able to save a lot of time and money by trying to troubleshoot car problems yourself. Air conditioning problems are quite common, and might be caused by any number of things that you can self-diagnose.
Check the coolant levels in the coolant reservoir. Lift the hood of the vehicle. Find the reservoir in the very front of the vehicle on the driver's side. It is a plastic white jug.
Lift the lid and shine a flashlight into it. Look at the side of the jug to make sure the level of the coolant is in between the low line and the full line.
See if the problem is a simple blown fuse next. If the temperature controls on the dashboard seem to work correctly but have no effect whatsoever on the air, this is likely the problem. The fuse box in a Toyota Corolla is located to the left of the steering wheel behind the coin tray. Pull up and out on the coin tray to remove it.
Make sure the control panel is working properly. If the climate controls do not work at all, then there is a problem with the control panel. Find the control panel by prying off the top instrument panel around the air conditioning temperature controls. Press the two fitting tabs in toward one another to release the heater control assembly.
Find the blower motor easily in a Toyota Corolla. If the air doesn't increase and decrease with the fan controls, than there is a problem with the blower. Unscrew and remove the glove box assembly. The blower motor is directly behind the glove box. Unplug the electrical connection, unscrew it and remove it.