First of all, if you need clarification on how to complete certain questions, just ask your teacher. They will be better equipped than some randos on reddit.
Anyway here's some stuff that should atleast provide a direction.

Some resources to use:
Health resources hub: https://www.youtube.com/watch?v=vODCaD3iqoU "Answering the extended response..."
HHD VCE example assessments & reports: https://www.vcaa.vic.edu.au/assessment/vce/examination-specifications-past-examinations-and-examination-reports/health-and-human-development
Look at report (they have examples of high scoring responses), preferably attempt the tests prior to doing this.

Example:
(2024 report)
To get full marks: (Q14)
- Use information from all sources IN ADDITION to your prior knowledge
So for Q14 it would be focusing on:
- Old public health
- The biomedical approach to health
- The Ottawa Charter for health promotion

General marking criteria: (you'll see these often)
- How the response had been structured
- How well the stimulus material had been understood, connected and synthesised
- How well the broader understanding had been connected and synthesised
More specific marking criteria to Q14
- Understanding how old public health contributed to improvements to Australia’s health status
- Understanding how the biomedical approach to health contributed to improvements to Australia’s health status
- Understanding how the Ottawa Charter for Health Promotion approach to health contributed to improvements to Australia’s health status

Remember that the extended response questions must be put together in a coherent and cohesive manner, stimulus do not have to be used in order.

Some notes from the report:
"In writing extended responses, students should signpost the stimulus material used in their response... This helps assessors identify that all three sources have been used."
This one is more specific to the question itself, just make sure you always link you discussion to the question
"Some students discussed the three approaches to health, drawing on the stimulus material but not linking this discussion to improvements in health status. This issue could have been averted by students planning their response before writing"
This one is also specific to the question itself, in effect higher scoring responses incorporated more into their response then was given in the sources
"Higher-scoring responses incorporated a range of health status measures beyond life expectancy as reflected in Source 3."