This might be a good topic for the Literature Discussion Forum, as you could collect ideas from more people there.
What is something that annoys you? As a tenth grader, surely you have gripes and frustrations in your life. Do you get irritated with the way in which cliques form at your school - the jocks, the cheerleaders, the nerds, and so on? Do you feel your school has been stereotyped unfairly because of the actions of a small group of students? Do you wish the menu in the school cafeteria was revised to offer more healthy options?
Outside of school, have you experienced the frustration of trying to find a job, only to be told that you shouldn't apply for a particular position until you have experience - how can you get experience working if no one will hire you? Are there complications with obtaining a driver's license in your community? Do your parents have unrealistic expectations for you, or do they allow your younger siblings to get away with things you were severely punished for doing?
Identify something that bugs you. Figure out exactly what it is about the situation that seems unfair, and go from there.