Greatest achievement

I’m writing an essay that ask me to describe an achievement I am most proud of. I don’t have many achievements in high school #:-S but I’m thinking of describing a mentoring club/program that I’ve joined and became a leader of. This club is already in my resume. Will it be redundant to describe my experience with this program in my essay? This is the only “achievement” I can describe.

You do not have much room in your resume to talk about the club right?

I think it would be interesting to write an essay on it, especially if there were challenges working your way up to the top. A detailed narrative of your journey to becoming leader of the club and why the mentoring club was important to you would be great.

Was there anybody special in the mentoring club that you helped? Telling their story and how you were able to help them and that was your biggest achievement would also be a great essay.