There are a ton of beautiful parks within driving distance! In order of increasing distance, some suggestions are Mount Diablo, San Francisco's parks, Muir Woods, Point Lobos, Yosemite National Park, and Lake Tahoe.
Our top choices would be Muir Woods and Yosemite since they are such unique places. However, we would not recommend these places if you are uncomfortable driving on curvy and steep mountain roads.
Northern California has some of the best wine in the country! Napa Valley and Sonoma are only 1 hour away. We recommend booking wine tastings in advance. If you want to stay near the hotel, Livermore has several wineries as well.
The Embarcadero is a great, family friendly way to hit many popular tourist destinations. Along the walk you can get tacos from Cholita Linda in the Ferry Building, visit the Exploratorium, try some sourdough as Boudin's Bakery, watch sea lions at Fisherman's Wharf, and get a chocolate sundae at Ghirardelli Square.
Our favorites parks in San Francisco are Land's End, Presidio, and Golden Gate Park. Golden Gate Park has a bunch of great attractions including The Conservatory of Flowers, Botanical Garden, and California Academy of Sciences.
For food, we recommend checking out Mandalay (Burmese), Brothers (Korean Barbecue), Dragon Beaux (Dim Sum), Sotto Mare (seafood), El Alambre (taco truck), and Salt & Straw (ice cream). Fun Fact: Tiki Bars were invented in San Francisco and so was the Mai Tai, so if you're over 21 go check out some out!