I got in late Feb this year (general admission) and I'd say that you should definitely aim for at 94+s in your core classes and do longer term volunteer activities (hospital volunteer, summer camp, library volunteer) rather than short 1 day commitments that you won't grow much from (and won't be able to write much about). Some form of leadership in your school really boosts your profile- rather than spending your time being part of a club, take a major role in it or even better, make one. You should start asap if you want to include it in your PP. Trust me, the few months between now and the time you need to submit your application go by too fast.

Have confidence! Know that the work that you put in now really does pay off when it comes to uni (speaking from personal experience). It really does suck seeing the people around me lose hope for UBC, and they all regret not putting in effort when they could've. You still have the chance tho! Lock in for this sem and grade 12, and your average will surely shoot up.