Air conditioner blows hot air.

Freon is no longer used, it's R134a. A non-working AC would never blow hot air, it would only blow ambient temperature air at best. If yours is blowing actual HOT air, then it's more likely a blend door in the heater box stuck open to the heater core and not opening to the AC coil.

See if the compressor even clicks on/spins , if not the system is probably empty from a leak , there's a safety switch so that it doesn't spin when empty ,, Some might tell you to get a can and put it in but then it'll leak out again . All components are set up to work together anyway , you should take it to a professional ..Don't listen to Johnny jerk wrench down the street .

I hope you're trying to charge from the low side of the system! What's the reading on your gauge. An empty system will be either zero or a vacuum. A system that has air in it will read excessively high with the compressor running. Without the compressor running your gauge should read about the same PSI as the outside temp. Normal operating pressure is about 35 PSI with the compressor running. Hope that helps! Jim