1.  You should be on the Properties tab.

properties tab

2.  Click the Add/Edit Questions button


add edit questions button


3.  Click the blue Add button, select New Question and then select a question type


4.  This will open the Question Editing screen.  On this screen you can 1) enter the text of your questions, 2) enter the text of your answers, 3) select the correct answer, 4) add additional answers if needed, and 5) give the question a point value.  Press the Save button when finished.