Good luck with getting back into shape. 7 years is a long time away, but your previous experience with training, and well as muscle memory, should help you a lot.

Have you been doing any exercise since hanging up the cleats? Running, swimming, anything to maintain some cardiovascular fitness? If not, I would definitely hold off on fitness testing until you have at least rebuilt a reasonable base and have some miles in your legs. Your current numbers won't tell you much, and to improve from rock bottom, you just need to ride, you don't need a crazy structured training plan involving analyzing every watt.

My advice (not that you asked for it, I realize) would be to just ride for a couple months and have fun. Wait until Jan and then test and start a winter training plan.