Well, this is an easy Job, just get the Shop Software, and a business-matching theme,
then, create an assortment of nice images, and start, to add Categories, Products, Content,
e.t.c., e.t.c., to reach your Goal.
It just depends on your Knowledge, technically, and when it comes to overall Design, and if
you even know, how to handle Web-Code, like PHP, then, you could also change or modify
existing Stuff, planned to look in a different way.
But if you don't know HTML, PHP, Servers, Databases, FTP, e.t.c., it is not quite so easy.
Then, you better get a Professional, because, just wasting a lot of time, to finally end up in Frustration,
is not, what you planned, I assume. BUT you CANNOT expect, to get MUCHO free assistance, when it
comes to a Software, like OpenCart. It's all about Business, for everybody involved, one should never forget.
Just to bring you down to earth...
Good Luck
Ernie