Mozart Wolfgang Amadeus and Joseph Haydn

Read the biographies of Haydn and Mozart in The Oxford Dictionary of Music and Musicians. Search Mozart wolfgang Amadeus, and Joseph Haydn on http://www(dot)oxfordmusiconline(dot)com.
We have more information about the early years of Mozart than we do about the early years of Haydn. The articles reflect that. Make sure that you present the two composers equally in your essay despite that.
These assigned encyclopedia articles serve many people - musicologists, amateur musicians, people with no background in music, scholars of European history, literary scholars, and others. To accommodate professionals the articles have information beyond the interest of the average person. One example in the Haydn essay is about Mattheson's Der vollkommene Capellmeister. The Mozart article also has many details about the Mozart family's travels. Do not get caught up with the details. It is important to learn how to read such details without derailing you from an understanding of the main points. Especially in the Mozart article there are many names that you probably do not know. You can find a great topic for your essay without understanding every detail of either the Haydn or the Mozart article.
Please note that the Mozart article has occasional quotations that are not in quotation marks. They are obvious, however, when you read the text.
After reading the articles at least once and taking good notes, organize your thoughts into some sort of outline. Read about each composer until about age 22. As you read each article for the first time take detailed notes. This will help you. Usually, one is impressed by details upon the first reading. You might want to read the articles (up until about age 22 for each) two or three times in order to come up with the main theme of your paper.
Work on the outline until you can focus on one or two main ideas. Write a draft of a title for the paper. Using your outline, write a topic sentence for each paragraph. Then start to write a draft the paper. Do not recite facts.