Tried to recharge AC in ford E-350 gulfstream ultra 1992. R.V. Driving to Arizona in 2 days

I bought a can of R-134a and it had a hose-a pressure dial and connection on it for the low pressure port.
problem is the connector on the hose is to small for the port.
it is a quick disconnect and not like a tire with a valve stem in it-i guess it is the adapter but it is to big for the connection on the hose… Are there different sizes?
do i have the right Freon? Do i need an adapter for the fitting on the A.C. Line. I'm confused. I'm going to Arizona in 2 days so i need A.C.

It sounds like you have an unconverted R12 system. 1992 was near the end of the age of R12 so it is very possible yours is still R12.

You and I can't buy R12 at any price, but licensed professionals can buy it at breathtaking prices - $50 per lb the last I heard. In any case, this is strictly a job for a professional.

You are trying to hook up to the wrong port, go to where you bought it, they will help you.

You need to check, it is likely that the system is R-12 and has not been converted to R-134A

If it is R-12 you will need to either find a source for the correct Freon (and expect it to be expensive) or you will need to have the system converted to 134A which entails removal of the compressor, draining the system, adding the correct oil and then recharging it

I found a conversion on eBay many years ago. All the advice I got was that it wouldn't work but it did.

Basically you remove the Schroeder valves to release the Freon, which in my case was empty. Screw adapters onto the valves, then fill with a can of oil. Once the oil can is empty, fill with the new gas.

Every one told me it would leak out, but my air con still worked when I sold the car 5 years later.