I think you have the right idea. Just roll with it that weekend, since it is your first time, I wouldn't book any special events. There are so many wonderful free seminars and tastings, as well as the entire world showcase of booths with small price tastings that will keep you plenty busy.
Just pick up the brochure when you enter the park, check out the schedule of events for the days you are going to be there. All the book/bottle signings will be listed as well as the free events and special things going on.
There are also wine walk abouts or walk throughs for a small price where you can taste a certain number of wines, you choose them from a list of many, again, for a small fee.
You are going to have a blast!
Enjoy