Before choosing a topic you need to consider how long you have until the paper is due, what audience you are writing to (you don't want to write a paper about climate control for someone who doesn't support climate control). You also want to make sure that your topic is not too broad. In other words, you cannot choose "Religion". You need to look at that and narrow it down from Religion, to Western Religion, to Islamic Religion, for example. You have take the broad topic of Religion, and narrowed it down to a "manageable" choice of Islamic Religion. Be sure you are capable of studying the information provided on your topic. In other words, don't get too technical or specialized in your topic choice. You are not an expert and don't have time to become one to write.
Once you have a firm idea of your topic choice, you need to find some sources to learn about your topic.