How to cope with the stress next year (grade 10)?

Next year I am part of student council and I have to attend meetings, once every month out of school. I feel like this might cause a lot of stress for me because of both the school work, and the extra curricular activity. I am very happy I am part of student council and I know I have to even my school work and extra curricular activities, I just want to try to keep my stress level down. I am also taking grade 11 university math in grade 10, so I am really worried because I want to get a good grade. I am a hard working student, I'm just somewhat worried that this might be too much for me? Any tips on how I can get both tasks done? Thank you.