The zoo is the big draw, especially for kids. You can also check out the Creighton baseball schedule and catch a game at td ameritrade park (now charles schwab or something). It’s a beautiful stadium. You can also check to see if anything is happening at the chi center. All three of these are no carry, btw.
Other things to check would be Creighton soccer or soccer or baseball games at Werner Park, which is very family friendly. Werner Park is in Papillion though, not downtown.