Are you going to spend your time at San Francisco in the next holidays? And are you going to use plane as your transportation to San Francisco? Yet, you are having no relatives in San Francisco so you cannot hang on whom as your picker?
San Francisco has all the answer for your confusion. The distance from SFO Airport that is located near San Bruno to the downtown is about 12 miles and taking feet walk should be impossible. Don’t be worry as San Francisco offers the SFO car service that is ready to pick you anytime and anywhere. The way to use the car service is easy, you just can find them on the internet then you may call them on their phone number or contact them via web to obtain their services, they also offer tour service for you.
Yet, SFO management is considering them as illegal. The official statement of SFO management is if you are looking for SFO ground transportation from SFO to the downtown, you may come to the information booth and ask for help. After all, whether you are going to choose the official or the unofficial one is absolutely on your hand to decide.