Gymnastics clubs vary, but usually classes are grouped by age, and as your child progresses in the sport, she/he will later be grouped by ability level.
First, find a local gymnastics club in your area. Clubs that are members of Gymnastics NSW, the state governing body for the sport, have to meet minimum requirements for liability insurance and coaching expertise and must pledge to follow Gymnastic Australia’s Code of Ethics.
Most clubs within NSW offer a trial lesson, this can easily be booked over the phone. If you child loves their class, you can then enrol them by speaking with the club reception.