Click drag means moving your pointer over an icon and then clicking on it. Then, without unclicking, moving the mouse to where you want to drop the icon. And then unclick.
Double click means moving you pointer over an icon and quickly push the left mouse click button two times.
Right click just means clicking the right mouse click button. This might be referring to right clicking on an icon. In which case you should hover the mouse pointer over the icon and then push the right mouse button.