So far, you have done the Joomla! part. If you just look for a way to setup a webstie, with previous steps it is good enough for this purpose. To further learn Joomla! CMS, you may look at the reference section to see additional materials.

To hold a web store, what is needed is to add the Joomla! extension called VirtueMart. VirtueMart consists of a number packages.  After download it and unzipped,  you see will them. These packages are called the extension of Joomla. 

 VirtueMart installation instructions found in their download website.