The stadium's food is far better than average with many special foods like garlic chicken and fries in addition to the normal ballpark hot dog fare. The food includes mexican food and many microbrews and drinks. Parking around the stadium is traffic clogged and expensive. It is highly worth your while to ride public transit to the stadium. Muni has created a streetcar line accessable from Embarcadero BART station which whisks you directly to the stadium.
Muni metro is a pretty good light rail system outside of commute hours.