Hello there, @sarah_stetson 
Welcome to the Canvas Community. Thanks for posting your question. Yes, you can upload as many files as you want to your course "Files" area. Further, you can then organize those files into folders...just like you would on your computer. You can then give your students access to the "Files" area of your course so they can download whatever they need. However, many instructors actually choose not to make the "Files" area of the course visible to students. Instead, they hide that button via course "Settings" >> "Navigation" and link to the files from content pages in their course. So, you could create all your modules with various content and then in some of your content pages, you would link to those files that you previously uploaded to "Files". Here are some resources that should be of help:
I hope this information will be of help to you, Sarah. Please let Community members know if you have any questions about this...thanks!
