The Ruler Options dialog in the View menu allows you to toggle the display of the Ruler ON or OFF, and to customize the spacing of the measurements on the ruler.
The Ruler appears at the left and bottom edge of each view, and can be toggled ON or OFF independently in each view.
A shortcut to quickly hide the Ruler, is to right-click anywhere on the Ruler, and select Hide Ruler from the popup menu. To display the Ruler again, you will have to use the Ruler Options dialog in the View menu.
Axes can be added anywhere on a view with the Axes option in the Tools menu.