I agree with many of the above posts, and maybe I have a few other ideas to add.
How long is your vacation here? If you have enough days, you can stay in either SF or LA for a few days and see many of the sights. Also, if you like the drive, you can drive from SF to LA and take several days. I have done that.
I always recommend: Visit places that are different from anything you could see at home. For example, SF and LA have fine zoos, but you can probably see a fine zoo near home. Some people like to hang out at big shopping malls. But if that’s what you like, you don’t have to visit USA for that. I’m sure there are big malls near you. You should look for things that are different.
In San Francisco:
Some places to see:
– I think you said you aren’t into museums. But you might like The Exploratorium – It’s definitely interesting. There is a fine classical art museum at the Palace of the Legion of Honor.
– Visit Golden Gate Park. Plenty to see and do there. California Academy of Sciences, several more art museums, a large botanical garden, many other specialized gardens, picnic areas – You could spend a whole day here.
– If you are interested in California history, visit the old missions like Mission Dolores. They all have historical displays.
If you have the time, you could spend a few days in areas around San Francisco – from the Napa Valley and Sonoma County wine country to the north, to Santa Cruz, Monterey, and Carmel to the south. If you like getting out of the city and exploring the smaller towns and country, and seeing the scenery, there is plenty of that if you just drive an hour or two out of town.
In Napa Valley and Sonoma County, there are many wineries, and many bed-and-breakfast places to visit if you like that. The drive up Highway 1 is spectacularly pretty, both north and south of SF. If you like hiking and other outdoor recreation like that, there are mountainous redwood forests with public parks and miles and miles of hiking trails. There are stables where you could go horse riding. You could visit Calistoga for wineries, spas, mud-baths and massages – there’s a spa in just about every block.
In Monterey, there’s the Monterey Bay Aquarium and many nearby places of California historical interest. Redwood forests, hiking, horse riding around there too. You could visit the beaches if the weather is nice.
Some people don’t like driving, and just want to get from SF or LA of Los Vegas as fast as possible. Other people think the drive is part of the vacation, and you might enjoy all the places and all the scenery. If you drive, I-5 is the fastest but also rather boring. Highway 101 is slower, but prettier, with much more variety – parts are in big cities, small cities, farmland, and by the ocean. Route 1 is the longest and slowest, and runs right along the coast most of the way. My suggestion: Take 101, with occasional side-trips to the coast. You could stop in San Luis Obispo (about half-way from SF to LA), and visit various cities around there. You might also stop in Santa Barbara and visit there.
My personal feeling is, you could spend your entire vacation in and around San Francisco and never run out of things to see or do. I don’t care much for southern California (LA and area). If you do go there, and if you like getting away from big cities, you could go to Big Bear, a small resort town up in the mountains near LA, where you could rent a cabin in the pine trees and go fishing by the lake.
That should give you a lot of ideas to think about!