San Francisco's public transit system is extensive and affordable. The Muni Metro and bus lines connect all major neighborhoods, while the iconic cable cars are a fun way to get around downtown. Taxis and ride-shares are also readily available, but can get expensive especially during peak traffic hours. Car rentals are not recommended due to high parking rates and heavy traffic. As a visitor, a Clipper Card is the easiest way to pay for fares on all transit options.
If you have more time, consider taking a day trip to nearby attractions like Napa Valley, Muir Woods, or Silicon Valley. For a shorter trip, skip Alcatraz Island and spend more time exploring other neighborhoods or checking out some of the city's world-class museums like the de Young or SFMoMA. Be sure to pack comfortable walking shoes and dress in layers, as San Francisco's weather can be unpredictable even in the summer.