How do I check if my licence is up to date

Annajd80 When you say that you don't see the plus sign when you work with charts in Excel for the Mac, that's because it simply doesn't exist on the Mac. So, it's not a fault of any kind.

On a Mac, you can add all chart elements by clicking inside the chart and then, in the Chart Design ribbon, select "Add chart Element" (the icon on the far left-hand side.

You'll find that almost all charting functions exist on the Mac, though they are in different places and some dialogue windows may look quite different from the Windows version that is used in the course.

Right-clicking (with a mouse) or two-finger-click (on a touchpad) on a chart element should work though.