Open chapter (extension: .chp) from your disk. A chapter contains all the preconfigured elements that you want to teach in one lecture. You can create chapters (https://teachit.study/docs-category/content-creation/) yourself or downlod them from the TeachIt library (https://teachit.study/teachit-library/). Of course, you can modify the preconfigured chapters to fit your needs.
Open the student view and share is with your students by projecting it on a beamer (extra display) or share is online via Zoom, teams etc. The student view does not have to be visible for most of these tools, but must remain open.
While teaching you move elements from the current collection in the teacher view to the scene. Whatever is created on the scene is mirrored on the student view.
Use the arrow elements to move between collections (green) and to move from one scene (=blackboard) to the next (purple). Use the annotation tool to annotate your content using different colors and pen-sizes. Further details are described here: https://teachit.study/docs/interaction-mode/