What do you plan to study after Year 12? Some courses have prerequisite subjects you need to take or you will not get in directly; you can research this online or via VTAC Course Search.
- Maths - is a good choice if you want to study STEMM (2nd M is medicine and other health sciences) or commerce courses in Uni, with Methods being the maths prerequisite if you want to leave the most doors open. Some courses e.g. nursing, will need some form of maths (so General U1/2 and/or Further U3/4 will fulfil that), while others don’t need maths at all e.g. law.
- Chemistry - depends on whether you are considering taking engineering, medicine/ biomed and related e.g dentistry (I think?) or chemistry related degrees. Chem’s a prereq for some of these courses.
Other than prerequisites for your future pathways, I’d suggest prioritising subjects you like. 
