In school one of two things will happen with your writing assignments: either you will be given the topic on which to write, perhaps even from a wide list, or you will be given the freedom to select a topic. Many teachers will provide the topic for newer writers, to help them ease into the process, but as you progress academically you will be given the freedom to pick the topic yourself.
Consider the list of potential topics below:
Make sure that you select something that is interesting to you. If you are interested in the topic your enthusiasm for it will show through your writing. You can find a great new angle that makes an otherwise old topic new and exciting.
You want to also find something that you already know a little bit about. This will make your project easier and will cut down the research time you have to spend finding rudimentary background information.
Once you have your potential topic in mind it is time to narrow it down to something manageable. In almost all cases students will pick a topic first that is too broad and they will be forced to narrow it down. This is true in almost all cases and it is perfectly normal. You want to be able to explore the topic and really prove the point you want to make in a small amount of space. So many sure that you refine your topic until you can really cover it thoroughly in whatever amount of space you have at your disposal.
Create an interesting way to approach your topic. Once you have reviewed a few different topics, you want to try and give your topic control and better define your thesis by finding an interesting way to approach the idea.