How do I add up this entire column of data without doing it manually?
Use the SUM function.
How can I find more sources?
Boolean operators and keywords, mostly. Let's look at what the assignment is about, what you've got so far, and see if we can't pull some new search terms out of those.
Where do I start writing this paper?
Let me answer your question with a question: what are you supposed to write about and what do you find interesting about it? If you don't find it interesting, that's fine. If there's no room for you to write it creatively, that's also fine. Let me offer some advice: write the introduction and the conclusion last. Both are a lot easier to write when you know what you've already written in the body.