This park is a 10 minute walk from the venue, on a trail that leads directly from where the ceremony is held. There is a playground, frisbee golf course, soccer fields, and basketball court. The trail itself is very nice to enjoy some marshy/plainlike nature.
There are many restaurants in the nearby area if you're looking for a bite to eat to hold over until dinner... Buffalo Wild Wings, Perkins, Noodles and Company, Takara's Sushi, Chipotle, Panda Express, McDonald's (across 494 on 55), Cub Foods, Hyvee, and much more!