Good information given regarding US30 vs I-80. I live in the area and avoid 30 if I can - even in my car.
There are two campgrounds, the National Park - Dunewood Campground is a few miles east of the Indiana Dunes State Park. Dunewood is much smaller and no hookups, but is a fairly nice campground. Not as scenic as the state park.
Indiana Dunes state park is one of our favorites for a quick get away. It was rebuilt several years ago and has updated electric service and very nice restrooms. It is electric only, but is a very nice park. They widened the campground sites and access roads so it is a breeze to drive through now.
The dunes and beach are a must see if you are in the area. They have great trails both walking and biking.