Hi, we were there November last year. There are toilets and solar showers plus a camp kitchen. No drinking water. In our opinion Lucky Bay was the better camp ground with better views and better beach. Le Grand campground had secluded sites but no views. I would suggest you head out early and when you get to the park gate they will tell you how many sites are available in which campground. Sorry cant help with the fishing. Enjoy
We were there in March 2016. At that time I would estimate about half the sites were occupied, so you won't be alone in March but you shouldn't have a problem getting a site. I assume it would get much busier right at the end of March and into April with Easter and then the school holidays.
Cape le grande is one of those places you'll never forget. Had a great stay in the Campgroubd and met some terrific people in the camp kitchen. Short walk over the dunes to a mesmorizing beach. We only tried to fish from this beach not elsewhere in the park. While we had fun we never caught anything. We found there was a line of seaweed out from the beach and if you cast over it the waves pushed the line back into the seaweed. Might have just been our timing though. Fun never the less.