This is how to add content to your library, start by clicking the plus sign at the top right of the screen. You have the option to create a new folder, upload a file, add YouTube video and add a URL.
If you're on the front of the library, you'll notice your only option is to create a new folder. This restriction is only for the front page of the library. Once you navigate into a folder, the other options will become available.
The add YouTube video add URL both require a link and a title.
Now, let's upload a file. Click the plus in the upper right corner, then click Upload a File, then on the Upload File(s) button. You will then have a selection window open from your local operating system. Now you can select either one or many files to import. If you are unfamiliar with how to select more than one file, on Mac use Command+Click and on Window use CTLR+Click. Once you have all the files you want to import highlighted, click Open to continue.
Next, the files will upload and process.
You can upload multiple files at once, and you can upload a vast variety of content. PDFs, videos, images, documents, and a few others.
After you've selected your files through the file explorer on your device, click add file.