To become a Personal Trainer you need to start with your Certificate III in Fitness.
This is the entry point qualification to work in the Fitness Industry. Cert III (Fitness Instructor) qualifies you to work in the industry as a gym instructor (in gyms, leisure centres and community health centres).
This equips you to conduct fitness assessments, create individualised gym programs, and conduct instruction on a one to one or group basis. Today most gym instructors complete Certificate IV as well, giving them a host of career options.