You can move the Document margins in the Document Inspector. To open the Inspector, click the Document button beside the Format brush above and to the right of your document window.
You can also adjust margins in the horizontal Ruler (View menu > Show Rulers).
Select the lines for which you want to move the margin, then drag the Left margin Stop (downward pointing triangle at the left end of the ruler) to the right, and drop it where it needs to be. The rectangle sitting atop the stop is the First line left margin stop, used to indent the first line of a paragraph or to create a hanging indent for that line. Make sure you keep it exactly aligned with the top of the triangle,
Regards,
Barry