I'm having trouble starting off this essay- how do I go about it?

Ok, first of all make sure you fully understand the question. Highlight key words, for example knowing if the question is asking you to 'explain', 'describe', 'analyse', or 'compare' two different scenes, characters or themes. Once that much is clear, begin to brainstorm. Perhaps on a seperate piece of paper, write down, for example, if it is two characters and how they fit into one them, the two characters names under a sub heading of the theme, eveyrthing that comes to mind when you think of that character. Even if it seems unrelated, or random, keep writing. Every thought you have regarding that theme, write it down. Then look at what is on your paper, and try and group points together, in a way they could be loosely related. Now you have your paragraphs. These will be the body of your essay. Take time to read through these, gage an understanding of what your argument will be and most importantly, if they essay title is a question, what your answer would be. Don't worry if youre not quite sure- the introduction and conclusion can easily be written after the main body of your essay- and this way will probably be much more coherent and fluent. Once you've got the main body, introduce it in an intro and summarise it, with points for development (for example, is it possible these characters fit nicely into another theme, or influence each other in some way?) in a conclusion. Good luck!