You can spend three days in South Lake Tahoe and the surrounding area. It is about 4 hours from San Francisco. There are daily connections to the city via Amtrak ($46). Lake Tahoe s ski resorts are world class. Indeed, it hosted the 1960 Winter Olympics. You don t have to actually ski to enjoy the area s natural beauty though. The lake is spectacularly blue, the forests are a verdant green, and the star gazing is top notch. You ll also have access to fishing, skating, gondola rides, and sleighing. There are plenty of casinos in South Lake Tahoe with buffets, shows, and the usual gaming diversions as well. Reno (more casinos) and Virginia City (historic Old West town) are a shuttle ride away. While the ski resorts themselves are expensive, there are plenty of affordable motels and B Bs in town. If you can stand the gaudiness and noise downstairs, the casinos themselves are always a great bargain. You can easily snag a nice, well appointed room in a casino for under $50.http://www.amtrak.com/http://www.bluelaketahoe.com/index.php
I don t know about greyhound. But, Sly Park is beautiful. It is about 1 hour past Sacramento
There is a hostel at Moss Landing off Hwy. 1 right on the coast with a lighthouse. I think it is a hostel where you can pitch in to cook and clean and stay for nothing but Im not sure of that. If you can figure out how to get to Half Moon Bay, there is a small bus that has a regular schedule down Hwy 1 to Santa Cruz. You can also go to Stinson Beach in Marin county. Take the bus from San Francisco to San Rafael transit center, then the bus to Stinson beach. It has a name and runs in West Marin.Maybe you should rent a car then you can go anywhere.