The page you use to interact with family & friends is a personal Facebook profile, it can't be viewed by everyone and it isn't intended for business use. Also, it doesn't have Facebook page tabs so you can't add social store to it.
To use social store you will need to open a Facebook fan/business page, which you can easily do in a few simple steps!
Read our eBay Seller Guide to Facebook Pages learn how to set up your new page, or watch the following tutorial:
Let me know if you need help with anything else.