I take it you have a mouse in your hand either your right hand or your left hand.
I hope there is two buttons or thing that go click when you push them on top or on the side of this mouse. If by chance you don't throw it away and get a new one. And if the new one will not work on your computer I suggest you also throw away your computer also.
Now holding this mouse I would thing your index finger would be on the left click button. You know your pointie finger, the one that you point at everything at, point, point.
Still holding your mouse your longest finger should be resting on the other button called (dah) the right button. Now I have found if the left button doesn't work for something the right one will.
Now lets say you want to copy something-------
holding down the left botton scroll (move over it) the something, text, picture or what ever and you will see that it become highlighted. ----- try it See the something is covered over with a color or become different. When you have finished 'covering' this something lift your finger off the button.
Then with your long finger or right button click and you will see a box (menu) appear see all those words appear like magic????? if you want to cut this something out chose cut, if you want to copy it chose copy. You do this by moving the mouse up or down. How that you have chosen what you want to do push the left button to do this cut or copy and it will highlight the word. This something is now held on what is called a clip board. It will remain there until you put something else there, or turn off your computer, which ever comes first.
Now go to where ever you want to put this something and left click and then right click and that magic box will appear again. You now want to paste that something so scroll down or up and again highlight that word and left click and wow it is all there someplace else.
Now if you don't understand that I can give you harder instructions.