Is summer school worth it?

Hi, I’m currently in grade 10 (YRDSB) and I’m deciding what I should do with courses. I’m taking all 3 sciences in grade 12 and 11, and i’m also hoping to take 2 maths (functions and calc) in grade 12. My school only has 1 math for grade 11s which is functions (for academic). I was wondering if summer school for chemistry would benefit me. Chemistry was one of the easiest subjects for me in science and I feel like having to manage 3 sciences and a math next year will be too stressful for me. Also, for sciences and maths in summer school can you pick between online and in person? and do you have exams at the end of summer school? and how were they like? Also, is taking 2 summer school courses difficult? For example English and Chem?