Unfortunately for the 485 post-study work stream my understanding is that a bachelors degree (AQF Level 7) at minimum is needed, a standalone diploma or trade qualification - and presumably an associate degree - would mean you are not eligible.
https://immi.homeaffairs.gov.au/vis...rary-graduate-485/post-study-work#Eligibility
https://immi.homeaffairs.gov.au/vis...rary-graduate-485/post-study-work#Eligibility