Say prost:It’s time for Oktoberfest! Join the party downtown on Friday or DIY yours through the month at Radhaus. Other cheers-worthy events in the mix include an Alter Ego pop-up at Kaiyō, whiskey tastings at Luma Hotel and Redwood Room, and aperitivo hour at Delfina. Plus, celebrate the return of the San Francisco Greek Food Festival and Portola Music Festival. --- Jump ahead to this week's top events: Dust off your lederhosen for Oktoberfest on Front. Be the change at the annual Califor...| 7x7 Bay Area