If you are staying near the venue, Apple Hill is a great place to spend the day. Check out their site for fun things to do. During the day you can travel from vineyard, to orchard, to bakery, to pumpkin patches! On the evening of October 21st they have Cider Sunsets at Hidden Star Camino from 4:00pm to 7:00pm.
If you are staying closer to Sacramento, the Downtown Commons is a good place to start your exploring. Check out their site to see what is going on during the day. In the evening, for some bars and good food, from here you can either head under the bridge towards Old Sac or across the light rail tracks to enter downtown Sac.