Right-click means use your finger to press that button on the mouse which is on the opposite side to your heart.
Task bar means that part of the screen which includes the green button with the word Start on it (but not the green button itself).
Select properties means point at the word Properties and press that button on the mouse that is on the same side as you heart.
Tick Show the clock means place the mouse pointer (see below) on the little square box next to the words Show the clock, and press the mouse button on the same side as your heart.
The mouse pointer is that little shape that moves around the screen when you move the mouse.
If you are not sure what a mouse is, post back...