How do I add text to my pictures?

Switch to the Graphics workspace, so you have the Essential Graphics Panel in view.

In the Program monitor, tap T (for Text) and either click/drag to create a text box, click inside the box, and start typing. OR click the Program monitor once to set a text line, and start typing.

Or ... in the Essential  Graphics Edit tab, select the New Item icon near the top, and select Text ... click in the box that appears, and start typing.