1. whatever you decide to choose, I wouldn't recommend picking more than 13 units, it's too much work, though if you're doing 4units of math that will cut it down much more than if you were doing more english/humanities subjects.
2. I have to admit at being surprised at you coming first with 93% - not that that's a bad mark of course - but you need to consider that in many places that might not have gotten that rank. in may school for example that would have put you at around 50ish i'd say. Too many people get 100% in 2U maths. Especially if they're also doing 3U.
3. Do you know what career you want to have? What courses you want to do at university etc? even if you ahve only a rough idea, this may dictate which subjects you pick.
4. Man people often have 13 units so that they are able to drop either a 1 or 2U subject if they find they hate it, so don't be too afraid to take on more than 12U
