Yes, you have to be precisely honest and quite revealing and candid to write a successful autobiography. And obviously, you need to describe some hardships of your life to show how you coped with that or how it influenced you. However, we strongly advise you to describe the thing that you feel rather calm about when writing. For example, you are writing about other students picking and making fun of you at high school. If you still feel like wanting to kill them all, it would be better to avoid this topic or mention it slightly. Why so? Because your feelings will leak into the writing and make your reader feel subconsciously uncomfortable.
Conduct basic research. Depending on your story, you may feel you need to do in-depth research on a certain subject, like air force pilots in WWII or life in a refugee camp in Poland. However, resist doing too much research before you start your first draft. You may get overwhelmed by the amount of information you come across during your research and start to forget your personal take on the facts. Remember that your memoir should focus on your memory of the event, rather than be purely factual or completely accurate.
Writing an autobiography for a high school or a college English class can help you gain a deeper sense of personal identity. An autobiography allows you to tell your story in a way that reveals truths about your values, goals and dreams. Though there's no exact science to writing an autobiography, you should include information about your background, major events that shaped who you are and any core themes in your life. Include specific examples to help readers understand your life history.