Hi,
There is no need to code or import anything for that. HikaShop can already do that by default, provided that you configure it properly.
If you want a page which lists your products, You can create a menu item of the type "HikaShop products listing" via the Joomla menu manager.
And if you want a list of the categories on the left of the page, you can create a module of the type "HikaShop content module" via the Joomla modules manager.
In the menu item settings and the module settings, you'll find many options to configure the menu item / module the way you want.
We actually wrote a long tutorial page which talks about all of this, and more:
www.hikashop.com/support/documentation/3...splay-front-end.html
I would recommend reading and following the instructions there. That should get you up to speed.