If a Holiday Park or Campground is genuinely family friendly they will promote it in their brochures or website info. A few other signs to look for are these things listed, If you find three or more then it most likely will be suitable for family camping and set up for fun.
A big plus with family friendly Parks is that there is lots of company for your kids and parents get to meet some other parents too.
Occasionally long term friendships are created when camping, this happened with my family when we camped at Ayers Rock Campground in 2000. The kids started playing cricket together then the parents met, we come from Victoria and the family we met was from Sydney. We just happened to be going the same way, so we travelled for another 10 days together and went to Kings Canyon, Palm Valley and Alice Springs and parted at Three Ways Roadhouse. Ever since then we have met every year and had some amazing travels together including The Kimberley, Fraser Island several times, Eastern Central Australia in 2008 and more.