Principal Park is just south of downtown Des Moines, so you're not too far from a lot of options. Just a block or two away is a bar called the High Life Lounge. Kind of a retro-70s type of place; Hamms and other crappy beers on tap, 70's decor, fun place to start the evening. Right next door is El Bait Shop, which is Mexican food and lots of microbrews on tap. Other restaurants in the downtown area are Legends, which is just a few blocks away. There are a couple of bars above Legend's: Liars Club and People's (good bands, sometimes), which are pretty hopping these days. A few other options in the Court Avenue area (2 or 3 blocks north of the stadium) are Court Avenue Brewery (decent local beers and a unique menu), Spaghetti Works, and Buzzard Billy's (cajun place).