How do I let customers upload files?

Hi, I am fairly new to building websites and I am working on a page that shows our company job listings. I want to be able to add in a feature at the bottom that allows the reader to upload their resume and cover letters if they wish to apply, but I can't figure out how to allow people to upload something to us!

Is there something I'm missing? As of now I have a button that sends them to an email form where they can write us their own email, but I am unsure about the functionality of that. I want an upload button!!

Thanks ahead for any help or ideas.