I understand the popular advice of enjoying your high school years and all, but some people do have really strong ambitions for a dream career at that age (which may be you!). In which case, nothing much else really matters or satisfies other than that goal.
Personally, I endorse your long sightedness and initiative to start preparation so early, which I regretfully lacked at your age. I was bumming around up until Year 11 when I realised that I really wanted dentistry, after which, I had to really turn on the boosters to try to catch up with other competition who already had a head start on me. Lets just say that my VCE years were a terrible strain on me and I do not ever want to have to go through that again.
There are many great examples here on AN that early preparation does yield incredible results, and if that is your goal, then maybe try to learn from the likes of Lzxnl, brightsky (99.95ers) etc. both of whom finished some courses by year 9!
Then again, this is just my observation.
Sure, it is important to enjoy the freedoms of Year 8, but don't waste away this precious couple of years that may very well be the key to your entry into med.