applying a gradient to an object

Hi guys,

i am new to illustrator and I am finding it extremely hard to use. It never seems to behave in the way that the tutorials suggest it will. In this instance, I am trying to apply a gradient to a simple object in Illustrator. 

I placed the object in the canvas. I then clicked on the object to highlight it. Then I opened the Gradient editor. Then I click the gradient button, and nothing happens. When I select the color swatches, I only have 2 color options - Black and white. The selected object simply remains black. no gradient whatsoever. 

Bascially nothing is happening. Can anyone help or suggest what I am doing wrong before I take my mac and throw it against a wall?

Thank you !!

P x