Create A Product On Drupal 7
You can use either of these ecommerce solutions: 

Drupal Commerce 


  Drupal Commerce is used to build eCommerce websites and applications
  of all sizes. At its core it is lean and mean, enforcing strict
  development standards and leveraging the greatest features of Drupal 7
  and major modules like Views and Rules for maximum flexibility.


or Ubercart.


  Ubercart is the most popular Drupal E-Commerce platform for your
  website. It implements everything you need to start selling products
  online. Web Developers from all skill ranges can use it to support a
  variety of E-Commerce industries-- including physical goods, digital
  downloads, or even subscription based billing services. Ubercart can
  do it all!