Once you have your assets you need to import them into your project. You can do this either from the windows file system by dragging them into the project folder or Xplorer itself.
Importing Assets Within Xplorer
Click File > Import. There are three options
Files: Import individual files from your file system. You can multiselect individual assets to import at the same time using ctrl or shift.
Folders: Import a whole folder of assets from your file system.
Asset Package: Import a whole asset package from your file system.
Navigate to the model asset you want to make a lesson with in the file explorer and select Import.
Choose or create a folder to save the asset to in your project and click Save. You can import your other assets (image, videos, audio) the same way.
Click File > New.
Select the imported model and click Create, a new lesson will be created with this model. You can also create new lessons with no model.