when i am on our apple macbook pro, i seem to be sometimes touching something that makes the writing on the screen either much smaller or very big font? what am i pressing and how do i get back to normal size from small please?
There are two ways to do that.
1. CMD and + or -
or the way I think you are doing it is by using a gesture on the touch pad. If you put 2 fingers on the pad and move them apart, the window contents will zoom in (larger), if you move those fingers back together thwe window contents will zoom out (smaller)