You already know one thing to put on the essay; this school can be of benefit to you academically. You need to expand briefly on how the school will benefit you. What else to you know about this school that is positive? Maybe put a few facts in such as what percent of grads go on to college or other schools (that would show you have done your 'homework) or something else that sets this school apart from traditional public schools such as this school focuses more on education or the arts, focuses less on sports, etc.

What do you know about you that would make you a good fit for this school? An essay that blends the positives of the school and your strengths would be impressive. I suggest you have someone in academia read it before you submit it.

Best wishes.