No A/C cool air from 97 Pontiac Sunfire air conditioner?

I bought a 97 Sunfire (2.2L 4 speed automatic) with A/C but it has never produced any cold air at all. The little light works when I click the A/C on but the air is just as warm as when the a/c is off.

I've heard about ways to recharge the A/C; is there some kit I can buy and would it work to make my air conditioning for this sunfire (or I suppose 97 Chevrolet Cavalier) work?

Is there a store in Ontario that would sell this?