Well, there are at least 2 ports on all A/C systems, and my Toyota has only 2... The high and low pressure ports (the subsequent ones are for bleeding on some systems). I have a 22RE, so I am not sure where your ports are located.

Easy check: Where your A/C lines enter the compressor, both ports may be right above the compressor. The one with the skinny steel line all the way is the high pressure, the one that converts to a larger rubber hose is the low pressure. Add the refrigerant/dye/oil mixture to the low side. After a couple seconds, your compressor will engage (add when A/C is on and at idle). You will most likely have to add around 16 oz of mix, so get 2 small cans.