There are many different essay styles and it is crucial to know what is expected of you. Universities, colleges and individual tutors will tend to have their own preferences and so it is important to make sure you know the right formula for your course. You can find a lot of information to help you online, but do check everything with your tutor or writing support tutor before you go ahead with writing your essay.
If you do not know how to write an essay, going back to college or starting a university course can be a daunting prospect. If it is years since you have done any type of studying, let alone essay writing, do not worry - most colleges, including online universities - have study skills information, including homework study tips and essay writing guides.