zoom out

I am really new at this so just bear with me.
When i start a window, the coordinates go from -2 to 2 for x and y. what is the best way to change this?

Use the gluLookAt function.

eye_x, eye_y, eye_z,
at_x, at_y, at_z,
up_x, up_y, up_z);

at---------------- eye

Or simply just translate into the screen: