Hello! Welcome to the forums, I hope you enjoy your stay :-)
Are you doing the HSC or VCE? Just wondering because you said you start year 12 in less than 2 weeks but most schools start this week.
In regards to what you said:
- Nope, don't waste your time summarising your year 11 notes. You're pretty much on a clean slate in year 12 - it's all new content from day 1 :-)
- For memorising, don't use linear notes if you know you're not good at it. Try something else! Writing essay plans including the cases and legislation you're going to use was more effective for me because while I had notes, I could refer to them instead of just reading them. Engaging yourself in class discussion also helps a ton.
- Make sure you do as many past papers as possible if you know you do well in essays.
Those are just a few tips -- best of luck for year 12!