A binder for holding loose-leaf paper is called a "3-ring binder" because it has 3 rings.
The green thing in the photo is a "3-hole punch". It is a device for punching 3 holes into paper so that it can fit into a 3-ring binder. You can also buy 3-hole paper with the 3 holes already punched in it.
The wooden stick is a ruler. It is one foot long (12 inches). A normal piece of paper in North America is 11 inches by 8.5 inches. We call this "8.5x11" ("eight an' a half by eleven") paper. Longer paper is called "legal paper", because it is used by lawyers for legal contracts.
