leadership position in orgs with minimal experience?

hello! i'm an SHS (G11) student, and i very much regret not being able to explore more organizations during my junior high days. i wanted to join some orgs in my school, however a lot of the times i find myself wanting to join the board of directors etc etc. however, i have little to no credentials/experience in any of them.

right now, i understand that i shouldn't sign up for those positions yet. but where should i start if i want to achieve one or two leadership roles one day?