You might want to reset styling when you are pasting text from another source to have the same font and styling as the rest of your course.
You do that in the course builder by selecting clicking on the text section so you enter text editing mode. A toolbar will appear when you are in editing mode.
The first thing to do is to select all the text you want to reset the styling for.
After you have done that, click on the reset styling icon in the toolbar. It looks like a T with a smaller x after it. The icon looks like this .
Finally, to remove all structural formatting click on the format menu to the right of the toolbar. It usually say Normal or Header 1. In the drop down menu select Normal while still having all text selected.
The following video shows the work flow.