Absolutely! We chose Lewisville for our venue so that families with kids could come, and let their kids run and play during the reception. There is a play structure close to where the ceremony and reception takes place, for the kids to play and get all that energy out.
Semi formal: your favorite summer dress, and slacks and a button up. It is at a park, so maybe hold off on your high heels.
Unless your invitation says "and guest", we would prefer that it's just you.
When you pull into the park, there is a big sign on the right hand side of the road that will say "Central Shelter - Owens/Rhodes wedding". Continue on that road, and you will end up at the Central Shelter. There is a parking lot right next to the shelter. It'll be a tight squeeze, but there should be enough parking for everyone.