Google Docs gives you full control of where your text is located on the page. From the ruler at the top of your document you can adjust the margins, indents, and tabs.
Margins affect the whole document. Change them by dragging the edges of the grey band on either side of the ruler, or by selecting File > Page setup from the menu.
With the margins set as you want them, you can click Set as default under File > Page setup… to set these as the default margins in all new documents you generate. You can also change the defaults that govern the orientation and paper size for your documents.
Indentations and tab stops work on a per-paragraph basis.
First line indent: Look for a small grey block on the upper half of the ruler. The position of this rectangle adjusts the start position of a paragraph; you can drag it around to set the start position for each paragraph.
Left indent: The left indent adjusts the position of the remaining lines. Control it by dragging around the down-facing arrow on the lower half of the ruler.
Right indent: The right-hand down-facing triangle sets the right-hand limit for a particular paragraph.
Tab stops: A left tab stop left aligns particular text to the tab stop, a center tab stop center-aligns it, and a right tab stop right-aligns that text. You can add a tab stop by clicking anywhere on the ruler where you want your tab stop to apper, and selecting the appropriate tab stop from the menu. Pressing the Tab key on your keyboard will then advance text from stop to stop.