From your Nearpod Home Page (My Lessons), Select "Folder" which is located next to the create button.
You'll see a pop-up window. Please name your Folder and hit "Create".
Next, you'll be able to add lessons to your new folder via the dropdown or by going into your main library and dragging the lesson into it. You can also change the folder color.
You'll find your folder on top of all your lessons. If you drag a folder into another, it will become a subfolder.