A template is a predefined collection of a layout, colors, design, and menu style. It is a starting point only; each of these elements can be individually customized.
Remember that templates are simply a starting point, a way to pick an initial layout, design scheme, color scheme, and menu scheme. Once selected, you can change each of these elements individually.
Navigate to the Control Panel > Website Tab > Setup > Look & Feel.
In the Site Editor Toolbar, click Templates.
Click a template image to select it, then click Save to preview your website with that template.