One of the beautiful things about WordPress is that you can separate the content of the website from how it looks, making the management of your website much easier. The look of your WordPress website is controlled by what is called a Theme. You can select or change your Theme at any time, too.
To get started, go to Appearance > Themes.
After you click on Themes, you’ll see this page:
There are a wide variety of Themes to choose from, each with their own set of options. To Preview or Activate one of the Themes for your website, just use the links under the thumbnail.