Grape leaves are a favorite food of several insects, not the least among them Japamese Beetles. Unless wholesale defoliation is going on, you might be wasting time and money to spray, especially at this time of year. So far as the variety, if you have grapes left at this point without spraying, they could very well be Concords. These require about the least amount of care here in the East. Concerning the pruning, that would take more time than I have. Contact your county extension agent (listed under USDA, Cooperative and Extension Service in the phone book). They might even be able to visit your place if it is on their route to somewhere. Often times they are too busy to visit a person with a few trees and a couple of grapes, but if you aren't in a hurry, they may be out. Since grapes are best pruned in the late winter, you have planty of time.