I don't have a customize shape option in my photoshop CC.  Why is this?  The only shape I can do is rectangle.

You do have to press and hold down the mouse more than a few seconds to see the fly-out menu of other shapes, or use the shortcut shift-u.

If you have already done that. Try resetting the Shape tool. Select it, and in the option bar, right or ctrl-click (Mac) on the icon, choose Reset Tool.

Gene