Most main tools of Brightspace rely on the text editor for creating content. You're going to see this text editor in the "Create a File" tool, item descriptions, announcements, assignment feedback, and many other places.
https://community.brightspace.com/s/article/The-new-Brightspace-Editor
This tutorial shows how to use the Brightspace Editor
The associated support ticket form covers all types of BrightSpace requests, including questions about the migration and training materials.