Being more active...
Leadership post are not just passive roles...
Perhaps you could voice out ur interest in holding various post like treasurer etc to your various CCA teacher-in-charge...
Wat sort of CCA are u in? sports? uniform groups?
Just go and get some job and work experience especially during your internship or school holiday, it will make your resume look good. Unless you want to get "bonus" point in applying to study in higher insitution like university, nowsadays employers hardly concerned about your grade and CCA etc as the first priority to hire you.. They just want to know if you have the knowledge and experence they want.