The "My Store" button in your ShopSite back office on the right hand side of the navigation bar is used to view your live ShopSite e-commerce website. You can configure the location of this link under Preferences > Hosting Service. This is also the link that appears at the bottom of the text email receipts sent to customers after an order is placed.
The "Help" button in your ShopSite back office on the right hand side of the navigation bar links to page sensitive help on ShopSite.com. If you have a question about a field on a screen in the back office of your ShopSite store, you can click the "Help" link to be taken to the help page specific to the page you are currently on with information about the fields you are viewing in the version of ShopSite you are using.