From a tourist perspective, there are options for getting around SF. You can take the Cable Car to/from the Wharf - this is always a popular 'to do'. And one of the Cable Car lines goes right by Lombard Street. Just like any other tourist spot during the summer, traffic, pedestrians, parking, etc. is all the same - crowded. Or you can take a taxi.
Just like SF and any other major US city, you have the financial hubs, tech centers, shopping, good & bad areas. But it sounds like you want to see the place where the Stars live and play. Any tourist book will list want you're interested in.
Nokia Theater - where all the stars gather for the blockbuster movie premiers.
West Hollywood - restaurants, stores, etc. - owned by and where you can potentially see a star.
Rodeo Drive - expensive shopping, expensive cars cruising around.
Malibu - where a lot of the big names live.
Highway 1 - ride by all the famous beaches from Malibu to OC. You never know who is in that hot red convertible driving by
Just for fun, you can go into one of the big department stores and play "dress up". Put on that surfer shorts and shirt, take a picture. The ladies can dress up, take a picture. Then put the clothes on the 'restock / put back racks'. Now these pictures are the fun ones that you can show all your friends and family back East and tell stories about
Enjoy your vacation out West