I have stayed at the Halls Gap Caravan & Tourist Park and give it a thumbs up. It is situated right in the middle of Halls Gap, with shops & Info Centre just a short stroll across the road - handy for coffee, icecreams, firewood, ice, lazily browsing souvenirs! A good way to ease someone into the whole camping thing.
There are stacks of kangaroos around. We had them grazing just metres from our tent. There is also a park & playground area between the caravan park and main shops - all great for kids.
We camped right up the back of the park, next to the creek which made me quite nervous as it poured with rain all night. It's also a bit scrubbier down that end, not as much grass covering as the sites up towards the front of the park. I'll find some photos for you.
Only some sites have fireplaces, be sure to request one of those.
There are several short walks you can do from the caravan park and some other excellent walks just a short drive away. Walks to Venus Baths & Clematis Falls start at the caravan park. My daughter loved the Grand Canyon walk which starts for the Wonderland Car Park (just a short drive away).
Facilities were clean & everything worked as it should.
Hope that helps and happy to answer any questions you have (if I can!).