Don't expect to be able to park easily, or for cheap or free. Street parking is always full, and full of pedestrians in the way. The lots near the event are $20+. Muni usually runs extra & custom bus routes up Van Ness to the event starting right near Civic Center BART. Bussing back after the event is extra crowded, but they again have custom busses that will line up right near Marina Green to take you back towards BART.