We have stayed at Dilli Villiage which is on the southern end of the island. It was a good spot, fully fenced to keep the locals out ( dingos). It had modern toilets and showers. its camp where you like and we set up near the water tank which had a huge light on it which made an excellent camp light and there was undercover cooking areas. Downside is that you do more driving because this park is down south.
The other we used was Cathedral Beach resort ,again a good spot with its own servo and shop. My thirsty V8 loved the servo. It has good toilets etc inc undercover eating area. we did have goanna's and one night we heard dingo's wandering around as the site isnt fenced, BUT we never had a problem with either the Goanna's or the dingo's
Oh another point to remember is that bins are not everywhere, for instance Dilli didnt have bins so we had to do a bin run up the beach to where the bins were, and cathedral had bins onsite which the goanna's loved hiding in. That made a memorable camping moment when you put rubish in a bin and find a goanna in there
Cathedral has a sandblow right behind it. Its a 15 min walk but well worth it.
Over all its lots of fun and you will enjoy yourself even if you get bogged, just look out for the tour bus's because they dont give way and they dont have to. Read the rules that they give you when you get your permits, its amazing that a tour bus gets right of way, and so does the plane that lands on the beach, look out for that also.
Have fun!! If you have any other questions that I can help you with feel free to ask here or email firstname.lastname@example.org