There are many types of papers and the type of paper you write will determine the content of the paper. Reactive essays, research essays, investigative and persuasive essays are just a few. It's a good idea to familiarize yourself with the conventions of the type of paper you write before you begin the writing process.
Determining the style requirements for your paper is not difficult. If the paper is a school assignment, your instructor will usually let you know what style guide you're using. This will most likely be APA or MLA. Some instructors aren't particular. In a case where the style isn't dictated, choose one of the style guides and base your paper on that style. See Resources for APA and MLA style guidelines.
Regardless of the type of paper you write, the structure will be consistent. All papers should have a title page with the paper's title, author's name and instructor's name. In some cases there will be an overview or abstract, then the main body of the paper followed by cited references. All of these elements play a role in the grade you receive for your paper. In most cases, instructors will require a formal outline of your paper as well.