I'm not sure exactly where they are on your 97 (I have a 94), but there are only two service ports on the A/C system. Each of them has a plastic cap that unscrews (they should anyway). If you follow the hoses of your A/C system around, you will find the two service ports. The low side port on my 94 is actually on the receiver/drier (the tank-like thing). The low-side port is much smaller in diameter than the high side, so that will make it obvious which is which.
That's all to answer your question, but I'm not a big fan of the recharge kits because they oversimplify the charging and A/C repair process and you risk doing damage to your system that could be more costly than getting it professionally repaired.
Read the sticky post in this forum on Recharging A/C-- it outlines the proper procedure so you can contrast that to what is provided in your kit. You risk overcharging and destroying your compressor, not to mention that the kit will not repair a leak. The sticky post on converting from R-12 to R-134a also has a good discussion on the use of kits (and the best way to use them if you must).
So you know, it would be best not to use a kit with "stop-leak" in it. Most shops test for this stuff and will not repair your system later if it has this in it. (Stop-leak damages their recovery equipment.)
All that said, if you are interested in learning how to fix your system right, there is good info here and people here will be glad to walk you through it. The last two times I took a car to the A/C shop it cost me $600-$700-- with manifold gauge sets for $40-$100 and vacuum pumps for $180 (or less if you find a place that rents), you can easily save a ton of money and still do the repairs the right way.
