ok first off dont be doing this stuff yourself if you have no experiance! mechanics need an a/c license for a reason. that **** is extremly poisonous!
so first open your hood and locate your ac compressor, start the engine and get someone to turn on and off the ac while you look to see if the clutch on the pullie engages. look at the pullie and you should see the middle start spinning when on and not spinning when a/c is off. if it spins then your a/c compressor is usually ok. also when it engages you should see your rpm flutter for just a second.
if it does spin you have a leak and need to have dye put into the system so they can find out where it is and what needs to be replaced.
