Put your curser at the beginning of the text you want to copy - hold down your left mouse button and drag the mouse over the area you want to copy. Let go of the mouse button. The area you want to copy is now a dark blue.
Click your right mouse button once, click on "copy".
Now go to where you want to paste it making sure you click left mouse button one time to place curser where you want it. Right click mouse button once, click on "paste".
Let me know if you need more help.