Unable to minimize windows or view more than one window
I had a MacBook Pro prior to the MacBook 2015. I never had a problem minimizing windows. I really need to have more than one window open at same time, but I can't seem to do this with MacBook. There usually is a white dot in middle where it was yellow in MacBook Pro to minimize the window. There is an icon with double page symbol I can click in the right corner, but when it shows a thumbnail image of each website on one page instead of minimizing the window when I click on it. Is there something I can click on to minimize the window so more than one window appears at the same time? I do not even see line/arrow appear in corners of window to drag the window to a smaller size.
MacBook, OS 10.10.3