As I understand it, under the main page of the repository there should be a button to create/upload new file to the left of "Username / Repository Name" in the GitHub web interface. There is not.
According to this question, I should be able to drag and drop while under the Repository -> "Code" tab. This is not possible either.
*Using Firefox, Javascript is enabled.
UPDATE
This is the page I am viewing: it is the main page for a selected repository. It must be the wrong the place. I have redacted my profile and repository name, but rest assured there is not a "Create New" or "Upload" button under any of them. The "+" in the upper right hand corner has been expanded to show there are no options like these here either. The portion covered by the expanded "+" button does not contain the links either.
Best Answer
GitHub's web interface will not show the File Upload button until you've made your first commit.
When working with Git, every repository needs to be initialized with a starting set of files to work from, typically, in the form of a README file. Strangely, GitHub does not allow you to make this first commit by uploading files from the web interface.
There are two ways to make your first commit:
Initialize with a README
When creating a new repository, you can check Initialize this repository with a README to create the first commit for you.
Push commits to an existing project
If your repository was already created, you can use the Git command line to push commits from your PC.