what can i do my heater is blowing cool air and making a clicking sound

You almost certainly have a failed temperature blend door actuator. The dash must be accessed to replace it. The tell-tale sign is the clicking noise when trying to change the temperature from where it sits now. Beware: some of these also had cracks in the heater plenum (the box that has the doors and houses the heater core, etc). These cracks also exhibited a repetitive click noise and would not adjust the temperature. However, replacing the motor does not fix it. Still, the more common fix is the temperature blend door actuator

Ther is a plastic gear in the blend door case that strips. It will nedd to be replaced. The case needs to be taken out.