The format toolbar (see Toolbars) allows you to align selected paragraphs, as follows:
Click on the Left Align button to align the paragraph to the left.
Click on the Right Align button to align the paragraph to the right.
Click on the Center button to center the paragraph between the margins.
Click on the Justify button to justify the paragraph (which alters the spacing between the words so that straight left and right margins are created).
See also: