The Magic Mouse is the Mac's default mouse, however it is somewhat different than a default mouse. This page has tips on how to work with a Magic Mouse.
Right Mouse Button
There are two ways to get a "right mouse button", by default you can ctrl + left click to simulate a right mouse click.
The other option is to change the mouse settings in System Preferences -> Mouse. In this menu you will find the option "Secondary Click" tick that to get a right mouse button on your Magic Mouse.
You can scroll on the Magic Mouse by moving your finger up and down on its surface.
The Magic Mouse has more options that are not shown here, to explore those options you can navigate to System Preferences -> Mouse. In this menu each option has a short movie explaining the option.
As an alternative you may want to watch the following tutorial: Youtube movie