1. Uploading files
To upload a file, first click on your folder where you want to upload the file. Then, click on "Add file" >> "Upload files" like in the image below:
You will be taken to a new page that looks like this:
Here, you first select the files that you would like to upload, directly from your computer. As you upload, they will show up below the "choose your files" section.
In order to keep track of what each upload contributes to the project, GitHub allows you to write commit messages for each upload you make. These are crucial, and should be short and straight to the point to let all of us know what it is you have contributed in your code. An example commit message and additional commit message have been left in the screenshot above.
When you are done, click "Commit changes" at the bottom (no need to worry about branches), and you will be taken back to the home folder of the project.
You'll notice that when you go back to your folder, you will be able to see two things: your new file (circled in red), and your new commit message (circled in blue). This helps everyone keep track of who is doing what in their files at all times.
For now, this is all you guys should need, since we are using GitHub only as a place to store files and not actually as a means of project development. If any other questions come up, I will include them in this tutorial.