Downtown along the waterfront are two new stadiums, one for ice hockey and the other for baseball. The Stockton Ports, a minor league affiliate of the Oakland A's, is a good central valley league contender to watch and an excellent ticket value given the comfortable ballpark. Wine is frequently served by local wineries for free. Night games sometimes feature after game fireworks. There's easy parking on neighborhood streets a block away to avoid paying for parking.
The famous Ernest Lawrence Thayer poem entitled "Casey at Bat" was written about a ball club in Stockton. Thayer first published the poem in the San Francisco Examiner in 1888. The poem is easily found at the second link below.
Equipment: None needed, except perhaps your sunglasses and water bottle. The fresh brewed beers on tap are highly recommended.
This multi-use indoor arena is now open and regularly features pro-ice hockey and big name musical talent. It's down by the ballpark and Weber point area, within walking distance of downtown. Browse the Stockton webpages for more information, but for wintertime sports watching and other events, this is one of two the places (See Bob Hope Theater). It's brand new, and has huge glass windows which look across the waterfront area toward Weber Point. Parking is easy in the parking structure, although free parking is generally pretty safe in the neighborhoods in the area.
Equipment: I don't know what the beer policy will be, but one should expect a gourmet selection of beers, wine, and food. This is a new stadium that won't stay in the tradition of the greasy hot dog only type sports concession.