Questions about dog parks...?

I'm moving to a new state where they have ample dog parks. I was just there for a visit with my Chihuahua who loved the park. I'm looking forward to taking my other dogs, but I'm a little weary because they are large (2 Boxers and a Doberman) and have never been to a dog park before. I didn't worry about the Chi because he is used to his larger brother and sisters, but I worry about how the large dogs might react to a pack. I'm not too worried about the Dobie, but my little girl boxer is a bit skittish with other dogs and strangers. Therefore, I could really use some opinions from those who have had similar experiences or are familiar with behaviors from new dogs. Any information would be most appreciated. Thanks so much.