Does anybody know how old you have to be to get your tongue pierced in SA ?
I think it is 16, with parents permission, but i am not sure, it may be 18 because of the area.
"Unlike tattooing, there is no minimum age for body piercing and no legal requirement for parental consent for children under 18 years in South Australia."
As far as I'm aware, the above is up to date. Despite the lack of laws around this, however, basically all reputable places that perform piercings will have their own rules around age. Most will not do piercings without parental permission under 16, and, if they're at all legitimate, they probably will refuse to do nipple and genital piercings for those under 18. Please do not go to a place that does not have these type of restrictions in place; chances are they won't really be terribly interested in upholding strict standards of safety.
You should be doing this anyway, but have a discussion with your piercer about how they sterilize the equipment. Be sure they know their stuff before they stick a needle through you. Viruses like HIV are often caught through improper needle use (not necessarily piercings, of course, but it is a possibility).