Setting up small ecommerce site

I want to sell a brand of waterproof sports wallet, which I import to New Zealand from France, here in NZ and in due course in Australia. I have set up a domain ending "biz" hosted by SiteGround in the US (Joomla which is all new to me) , and am a long way towards designing the very simple site from one of their templates ; but I am an amateur!. I have also signed on for Zencart, but can't seem to see the shopping cart stuff on my site. I need professional help in getting it up and running and publishing the site so I can get on with selling!