Before opening your store you need pieces in your store. Before that you need to set your store up. There is a lot to do here. Click on the My BL tab and go to the Settings under Account.
This will take you to a new screen. On the left of the screen there is what is below. Each one of these you will need to set something up in for your store to work correctly.
Display, Management, Terms, Splash, Shipping, Payments and Message Templates. I will walkthrough the steps for each one of these headings. I will only cover the most important parts of each page. There is more on each page to look at but not everything is important to get your store running.