A couple of things for you to consider:
1. Why would your instructor not provided you with an overview of your training, including exams? Might be worth asking for this, if the response is anything other than you being provided with a written overview I would be looking for an instructor who would provide this. You don't want to get to the RPC flight test and discover you need to sit for an exam(s) you haven't prepared for. It's much easier to learn little bits along the way than to cram over a few days. You'll also retain more of the information if given the chance to apply it to your flying. HF would be an example.
2. This type of question can be answered by referring to the RAAus Operations Manual (OM). You should become familiar with its content, without becoming too hung up on it you are legally required to comply with its directions. As a solo pilot (pilot in command) you become the person responsible for the aircraft, not the instructor.
Here's an extract from the OM (Section 3.01) regarding examinations prior to first solo flight. I think it is accepted the Radio Endorsemet exam will be complete too, although there is no direct statement as such in the OM.
STUDENT PILOT CERTIFICATE HOLDERS
Solo Flight
2.
Prior to undertaking a first solo flight a Student Pilot is required to pass a written PRE-SOLO AIR LEGISLATION multiple-choice examination set or approved by RA-Aus, which shall include a minimum of five (5) questions specific to the procedures at their training aerodrome. The examination will be conducted at an approved RA-Aus FTF.
Good luck and enjoy your first solo, many thousands of hours flown since mine 36 years ago, I still remember it like yesterday!