Right across the railroad tracks is Downtown Fullerton. Many fabulous restaurants within walking distance. We ate at the Greek place, left my car parked in that lot then just walked over the bridge to the theater. So convenient.
Park next to The Maverick Theatre and walk across the bridge over the train tracks to one of the restaurants near Commonwealth Ave. I suggest Hopscotch, Kentro or El Amerikano. Can't go wrong at any of these spots :)