WP Statistics adds a top level menu to your admin interface in WordPress, you should see this in your main admin page (image on the left below) near the bottom of the list, clicking on it should bring up the additional items (image on the right below):
Each of these options will be discussed in the following sections.
In addition, if you’ve enabled the option, you may also see the WP Statistics menu icon in the main admin bar of your site as such:
This menu gives you a quick summary of what is going on with your site.
Check out this article to learn more about all the available options.