how do i know if my compressor is bad or is the clutch frozen

Usually if the "Hub" for the AC compressor clutch will not turn it means that something inside the AC compressor has failed and caused the compressor to lock up. To answer your question the compressor has suffered an internal failure causing it to lock up. I would suggest you take it to a qualified mechanic to evacuate the system and replace both the compressor and the inline filter along with flushing out both the evaporator (radiator inside the dash that blows cold air) and the condensor (radiator in front of the engine radiator that removes the heat from the freon) along with the lines. Usually when an AC compressor locks up or fails it sends tiny bits of steel and aluminum through out the system. If you have the compressor replaced and they dont do the flush out these tiny bits of metal will destroy your new compressor.