Moved from Photoshop Elements forum.
Have you got the windows maximized?
Otherwise, OSX allows you to resize the window a program occupies to any size you want.
BTW, do you have a Retina monitor? Sometimes the utlra-high resolution monitor messes up the way some programs display.
I was able to resize the window and see the bottom menu by clicking "command" and the green button, top left.
Excellent. That's the Maximize Windows command I was referring to.