Click on the "Edit Site" button next to the website builder you want to use.
Click on the "Statistics" option on the left-hand tool bar.
Here you can find statistics for your website's visit count.
At the top of the page, you should see a "Total Visits" count, and on the right side of the page you can find a breakdown of which pages receive the most visits on your website.
In the center of this page, you'll find a graph showing how many visits your website has received in a set time frame. You can use the two drop-down menus to view a particular year or month, or set them both to 'none' to view an all-time graph.
If you'd like to view your store's statistics, click on the "Store" toggle in the top-right of the page above the "Total Visits" count.