The Verdict: Need More Info
You are too young to apply now; the arrangement opens once you turn 18, and you will also need at least two years of university study. Come back when you meet both.
The arrangement rests on a Memorandum of Understanding signed in Canberra on 14 May 2014 and ratified by article 1 of Law 4353/2015. It offers 500 places a year, to people who have turned 18 and not yet turned 31, for up to twelve months, and needs a degree or at least two completed years of undergraduate study.
The Greek side is run by the Youth Directorate of the Ministry of Social Cohesion and Family, and visas are issued by Greek consulates in Australia.
If your family has Greek ancestry, our Citizenship by Descent quiz is worth taking now: descent has no age limit and gives citizenship.