Onsite camping is awesome but loud at night for the little one. I've heard of people getting together and making little areas of families that are toned down a little. There are two parts of on-site camping. The north part is tent only and the south part is tents/vehicles (you would need a vehicle pass for the vehicle). It fills up quick on Thursday night, but spots can still be found on Friday. There are tons of families and kids at the festival, none of which are mine, so I can't give you much advice there.
Listening to: Lindsay Lou and the Flatbellies