This is where you can change the look and feel of your site.
Note: When you first create a WordPress site you will be given a default theme.
You can only have one theme at a time, but you can change the theme already installed or by installing a new theme.
Note: The menu items and layout of a theme may differ from theme to theme.
Changing the Theme
To change a theme select Activate on the theme you would like to use.
Note: You may have to hover over the theme to show Activate.
Install New Theme
To install a new theme select Install Theme and decided how you want to chose a theme.
If you want to look at theme select the Search button, Newest, and Featured.
After you have found the theme you want you can select Install Now and after it installs select Activate.
You can browse free WordPress Themes here http://wordpress.org/themes/.