It is possible to recover activities and files inadvertently deleted from a Moodle course.
Faculty can recover deleted files and folders for up to seven (7) days in their Moodle courses. Once an instructor deletes an item, it will appear in the Recycle Bin. The Recycle Bin is located at the bottom of the Administration block.
The image above shows the Course Administration block with the Recycle Bin listed at the bottom of the list of links. Items are easily restored from the Recycle Bin. You can learn more about the Recycle Bin in this video (1:33).