Hi Mark,
Due to the light pollution dome around Gympie you may need to travel just a little out into the country to find very dark sky, 2 areas I have not visited yet but will do so soon look promising for dark sky and good camping, check out the links to google maps and photos of the areas.
Glastonbury Creek Camping Area
Bortle Class 2 dark sky
https://maps.app.goo.gl/rWJd6zCMxaqhh3hu7
Teebar Sports & Recreation Grounds
Bortle Class 1 dark sky
https://maps.app.goo.gl/gT7PAgsAGuKYNuAY6
Regards,Wayne