If you on campus early, stop by the Student Union around Noon when the Cal Band comes out. They will perform for about 15 minutes before marching up the stadium. Across the street is Bancroft Clothing where you can find all kinds of Cal stuff and the prices are lower than the officially branded things in the Student Store. There are lots of dinner choices in Berkeley so you might use yelp.com as a search tool for starters. We like the Townhouse Bar and Grill in Emeryville, about ten minutes south of Berkeley near Oakland.
We are in Section I and will be in the shade all day. If you are situated on the east side of the stadium, be prepared for the sun from start to finish and bring your sunscreen and cap or hat. They also recently installed security screeners before you enter the stadium so be ready for some delay as your bags, clear ones only, are searched and you must go through the scanner. We were not prepared for this at the first game, so we were surprised at the time ti took to enter the stadium.
Remember that the California Memorial Stadium is located on a hill above the main campus so be prepared to walk about a half-mile or further from where you parked your car. Bring your walking shoes, cap and enough H2O and you will find the stroll through campus a very pleasant one!
In any event, enjoy the day and it will be an usually warm one in Berkeley and surroundings.