There are 2 knobs beside the gear lever. Place your hand on the middle knob

Turn it right (clockwise) once to turn on the aircon with the fan speed at level 1

Turn it more to the right (clockwise) to increase the fan speed

The third knob on the right would be to adjust the aircon temperature. To lower the temperature, you will have to turn the knob clockwise

Turn the middle knob to "0" and the aircon would stop blowing out air