"The opportunity to teach something you know" - GED Prep Class Essay help

I've always been horrible at starting essays and this is no exception. My topic is as follows: "Suppose you had the opportunity to teach something you know to someone else." Yes, that's all. What I know so far is that my answer, if you could even call that a question, is that I would teach someone how to take better quality photos. I have no clue how to start that or where to go from there. Any help appreciated, and I'm not expecting you to write it for me, just help me with ideas.

If I had the opportunity to teach something I know to someone else, I would teach someone how to take better quality photos.

There. Not the most original or scintillating opening sentence, but it gets you on your way, and can always be rewritten later. Now, why would you choose that? Is it that you believe that taking high quality photos is important? Or that it happens to be the one thing you believe you're truly good at? Or that it would provide your students with some specific benefits that you wish them to have? Your answers to these questions might then give rise to still more questions, and so on, until, in chasing down the answers, you find you have enough material for a complete essay.

Or, you could follow up the thesis sentence that Sean provided not by saying why you want to teach that but by actually teaching your reader. Indeed, your instructor may be wanted to see informative, rather than persuasive, writing for this assignment.

What are three key things people need to know to take better photos? Devote a paragraph to each of those, say something in the introduction and conclusion about the joys and benefits of photography, and you're set.

Yes, your topic is a bit vague, as it isn't a question so much as a statement. You might want to check with your teacher to see what she meant by the prompt, because if she is looking for a persuasive essay, then taking Simone's advice would be disastrous, whereas if she is looking for an informative essay, then taking my advice would be equally bad. So, you need to figure out what sort of assignment you are writing before you do anything else.

Right: It's always a good idea to ask for clarification from teachers rather than just guessing what they want. And, these days, you can often ask by email rather than waiting for the next class session.