how to change background on photos

I only now read this reply and noticed it already showed a (1) thumb down.
Since I did not place it there, I was curious who did and why, so I clicked on it
hoping to find an explanation, but instead it changed the (1) to a (2).

Just want sandraseeves to know that I appreciate the interest and time taken
to help. I will definitely try out all helpful information I've received.