Unfortunately, I cannot help you with the content of your essay. As I do not know what the specifics of your assignment are, I am not sure as to what kind of information you need. If it is an opinion piece, what classes do you think are not necessary for a major? If it is a research paper, I suggest you begin with an internet search using keywords such as "unnecessary classes" and "college majors"; otherwise, you can contact your academic advisor or campus library for research materials that may be able to assist you.
Once you have your content together and have written a rough draft, I can help you with organization and editing. Good luck!