Where is the air conditioner drain hose on 1994 Chevy Corsica?

There isn't a 'drain hose'. Refrigerant is recovered through the schrader valve on the high pressure side of the system. This type of work should be done only by a certified tech, as not only is it illegal to discharge refrigerant into the atmosphere, but handling refrigerant also poses significant dangers to people who don't know what they're doing.