Central air not cooling. Options?

After 25 yrs, our AC doesn't cool right. I've cleaned the outside unit, changed the air filter, etc. I imagine it is R-12 coolant. If its needing recharged, what are my options, and how much can I do to facilitate repairs and save money? Can more modern coolant be used? What about alcohol-type coolants? Any ideas appreciated. Thanks. Wrong forum, sorry. Hope I get the hang of this. Lot of good brains out there I could use.

 

Welcome HoaryMug:
Most residential air conditioning of that age have R-22 refrigerant. Make sure your compressor is running, just touch the valve on the line to see if there is pressure in the line.
At 25 years you have gotten your money's worth out of the system; it may be time for a new Goodman/Janitrol unit, which is the best buy in my opinion.
Glenn