Up here, grade 11 physics is mostly kinematics: Velocity, acceleration, force, energy, gravity, pendulums, friction, etc. Grade 12 physics was things like electricity and magnetism, very basic quantum mechanics, and that sort of thing. So far I've found grade 11 physics to be far more useful for my university courses. My E&M course retaught everything that was covered in grade 12 physics, except way more in depth. It seemed like everything I learned in grade 12 was just very limited, special cases of what was learned in the university E&M course. I can't say having done it in grade 12 really helped a noticeable amount.
All that said, I would just try to be comfortable with kinematics: force, energy, acceleration and all the stuff I listed above. I would say that in preparation for what I assume is calculus based physics, being comfortable with the concepts would be more important than solving problems, although solving problems is useful for building that level of comfort. You should really be able to instantly know what all those kinematic concepts are, and very quickly know the relationships between them (e.g. knowing that Force=(mass)*(acceleration))
If you're already comfortable with that, then the next step is probably to make sure you're comfortable with calculus. Most of what killed people in my E&M course wasn't actually the concepts, but just that they weren't comfortable with the calculus required. Especially focus on applications of calculus to real-world problems, and try and understand how derivatives and integrals fit into a real-world scenario. A lot of introductory calculus books will say things like "This problem is modeled by this derivative, now solve for _____." Don't just blindly solve it from that point, because solving a derivative or integral is usually the simple part. The hard part is generally figuring out which derivative or integral you actually need to solve your problem, so try to understand where the formulas are coming from. Even if you did do very well in your calculus course, most intro calc courses only focus on solving integrals and derivatives. Don't get me wrong, being good at that will help, but figuring out exactly how to use this 'new math' to solve a problem can be a lot tougher than you might think.