According to WorkCover, people cannot start driving forklifts until they are 17 years of age or hold a Certificate of Competency until they reach 18 years.
According to Australian Forklift Training , young people can start to drive forklifts under the direct supervision of someone with a license once they turn 17. They would have to fill out an operators log book and log all their practice hours, which is similar to how they learn to drive a car.
Training manuals can be given to them, so that they can start to learn the necessary theory knowledge required to get a license. As soon as they turn 18 years of age, they can sit for the assessment and get the license.