I tried these cms, they are really good, while wordpress is easy to use then Joomla needs your knowledge on its system.
These two are created specifically for content management. That is why in their original form, they do not contain e-commerce sections.
As time has crept by, Plug-ins and component developers have designed e-commerce applications for the two.
In view of this, if you wish to use Joomla or WordPress for e-commerce, you will have to contend with several utilities that are not e-commerce oriented such as Links, Articles, Comments, and Image Galleries among others.
E-commerce solutions such as OpenCart and TomatoCart are what you should be going for if you insist on e-commercial ventures.
So, if you are not expert in web design field, i would suggest you try wordpress, easy to customize, more plugins and frienly with users via its templates (include free and paid themes), it call as responsive design.
Hope it helps.