Airconditioner blows Hot for first 20 minutes

Try resetting actuators by pulling fuse 50 under h ood for 60 seconds with key on then reinstalling. I am assuming compressor is kicking on and large pipe under hood is cold with in a few minutes. Then it will have to be scanned for codes by a mechanic. If this is auto temp control where you set the temp inside car then it will have to be scanned for codes as a sensor may be bad causing it. You can also check fuses in body module if you can see any and try fuse 48 it's under right kick panel. But those may be internal

Autozone will not be able to read the codes on hvac they can only read engine/trans codes some abs codes a mechanic has to use his scanner to read it.