To answer QwaQwa7803, you can use the Headmaster's computer to purchase a cafeteria for the school assuming you have progressed far enough in the game to unlock this. Use the hints from the reply menu if needed to advance quests.
The cafeteria is in the middle of the map ... once it's built and staffed. If you don't have the option on your computer to build it yet, or you haven't added the cook and her daughter to your school, follow other storylines in the meantime until they show up.
