I want to know what a context menu is and where do I find it?

I am working on a book. I want to single space, but, it keeps double spacing when I get to the end of my first sentence. I clicked on help and it said to click on the context menu then on single space. I have no idea how to do this.

Janice

Place the cursor in the first line and click the right mouse button. This will bring up the context menu. Select in this menu Line Spacing > Single.

Are you using a special template for book writing? The standard template normally is set to Single Spacing.