Low pressure port

Air Conditioning problem 6 cyl Front Wheel Drive Automatic 165000 miles

I cannot find the a/c low pressure port in my engine. Where is it located?

Sorry to be such a dumba** but I am having trouble orienting the diagram to my engine. Does FRT mean the front of the car? On which side of the car are the a/c hose routing and service ports located? If you could tell me where this diagram is in relation to the overflow container where I put in antifreeze, that would help. I also know where the battery is, where the oil dipstick is, where the power steering fluid goes--if you could tell me if this diagram is near any of those things that would help me find it. Also, does the port have a cap on it? Again, sorry to be such a pain but I am a helpless woman with limited mechanical ability.

Thanks so much.