You are going to need to have the blower motor checked. If it is getting ready to go you will notice that it is very weak air coming through the vents.
You need to check the ducts and make sure that they are not smashed down or blocked. Also make sure that they are connected and sealed properly and not leaking out air. Get the motor checked out or make sure it's turned up to a higher speed.
Check correct setting of the inlet and outlet panels. If necessary, clean inlet and outlet of your HVAC. Clean evaporator. Position your A/C so air can easily access and pass the unit. In case the evaporator is icing during operation check system charge and controls.