All site's are automatically published on the web immediately. Click on the "Go To Site" button at the top of the admin area to be taken directly to your site or type the site URL into your browser's address bar.
Some merchants assume their site is not published when they search for it in Google and no results appear. It normally takes several weeks after a site is created and published before it will be added to the search engines but this does not mean that the site is not published, it just means that it is not yet indexed by the search engines. For further assistance on this topic please see How do I get search engines to list my site?