The Principal
Who: The boss of your building, plus the assistant principals and deans who handle the day-to-day. Everyone sees them, so everyone assumes they call the shots.
Power: Real, but narrower than it looks. Principals run school-level rules: discipline, how the dress code gets enforced, grading and late-work rules, events, clubs, and what happens in the halls. They usually hire the teachers in their building and often build the class schedule, which decides which electives run and who teaches them. Spending money is another story: once salaries and fixed costs are paid, some principals control only a few thousand dollars a year. Anything big (start times, curriculum, the budget) needs a yes from the district.
What they care about: A calm building, no angry parent emails, decent test scores, and staying in good standing with their boss at the district. In a small district that's the superintendent. In a big one it's usually an area or assistant superintendent who oversees a group of schools.
How to work with them: Bring rule problems, not money problems. Ask the main office for a 15-minute meeting and come with one specific ask, proof that other students want it (survey results, a list of names), and a plan that makes it cheap to say yes: a one-semester trial, with your group doing the legwork. If they say "that's a district thing," ask who at the district owns it and whether they'll pass your proposal along with their support.