Tutorial files are available in the main library. Scroll to the bottom of the list and add files to your romm just like a game.
Alternatively, go to https://virtualtabletop.io/Tutorials and see all the tutorials available in one room already loaded.
Then you can read the descriptions, play around with them, and look at the widget definitions in edit mode. Please do not alter the versions in the Tutorials room, but feel free to edit any you upload to your own room. If you make an improvement or want to develop your own tutorial, check out the tutorial channel on Discord.
All tutorials used on virtualtabletop.io have the approval of their developers to release the tutorial to the Public Domain under CC0. The graduate icon in the library images is from https://fontawesome.com and is available under CC BY 4.0.