The insertion point is a small vertical line to the right as you type. Observe it while you type. You can place the insertion point from one point to another. Move the mouse around on the screen and observe how it looks. When you have to type the pointer turns into an I-beam (much like a capital I).
Another option is the zoom option. Use the zoom option to make everything on a webpage bigger or small. Click the zoom option on the top right of the web browser and select 10%, then 50%, then 75%. The screen size will change each time. This is important when you doing some exercises on this site.