Advice from Engineering majors who did IB?

So I'm starting grade 12 this year and I'm not sure if it works the same for all schools but I finished my SL math and SL physics courses in grade 11, and now I have HL geography, HL Chemistry, and HL english to focus on in grade 12. This kinda leaves me with a 1 year gap of doing like ANY math and physics between grade 11 and university, so i'm wondering if there was anyone in the same situation as me and what you would suggest I do to better prepare myself?