Next year, I will have to apply for new courses, but how do I find the courses I need?

First of all, I need to know which courses will be most important for me and which courses I will be taking over the summer. Also, for me, I will be taking the Synergy Courses and I will have four choices left which I must choose very carefully. I will be taking math 11 over the summer, so I will apply for math 12, I'm thinking of continuing French, so I'll take French 9, I'm thinking of continuing band, so I'll take Intermediate Band, but I think I'm already fit, so I'll see if I can take something else instead of P.E.