San Jose Mineta International Airport is the closest airport to Cupertino. Southwest, Alaska, American, and a few other airlines fly in and out. See travel tab for more info.
There will not be bus to transport people to the ceremony or the reception. There are plenty of ubers and lyfts, so people can make their way to cocktail hour as they are ready. However, there will be a bus that does rounds at the end of the reception. However, there are also ubers and lyfts if you don't want to wait.
Downtown Los Altos is only a block and a half away from the church. You can walk down the main street, pop into a book store, grab a cup of tea or coffee. You can also go back to the hotel and relax. Picchetti does offer "discounted" glasses of wine to pre-wedding guests OR, you could do a full tasting, as they have many more wines than what is on offer at the reception. This would also be the time to come if you're wanting to purchase any wine to take home for yourself.
Cocktail attire: short or long dresses and suits. There will be gravel and grass at the reception site, so non-stiletto shoes might be best. We'll also be dining al-fresco, so, while California in October is very mild, you may also want a shawl or jacket. There will be heaters.