When you are building lessons in the editor there you might not easily found. Here you will find a quick breakdown of where things are in the builder and a few fun items you might want to use.
Basic Text edits: Bold, Italics, and Underline
The text option dropdown gives access to the rest of the text features.

Here is what the dropdown for the text editor looks like:

Next you will run into the alignment and paragraph dropdowns

The next section of icons includes:
Add Link
Add Image
Add Video
'+' which drops down more add options
