M.P.
We've loved camping with our toddlers. They take the lead from mom. We created nests at night and brought along a favorite blanket, pillow and stuffed animal. We at times had a lot of stuffed animals (although I worried about getting them dirty, my husband assured me that they were meant to be used and this was a great opportunity). It's a wonderful experience for the family to have new adventures together. My children also loved books on tape that they could look at while listening. Now I suppose it's CD's, but something simple just to look at. We also had a deck of cards - 52 things to do on a plane ride. But I bet you'll get lots of entertainment ideas from mamasource.
The one thing that I'd focus on most is for you to have a good time and look forward to it. Your enthusiasm can be infectious and your child may not remember this particular trip, but will have an open mind to trying new things. Good luck! Blessings to you and your family.