get category by name function?

-- HikaShop version -- : HikaShop Business 2.6.3
-- Joomla version -- : 3.5
-- PHP version -- : 5.5.12

Hi,
Is there an existing function that whenever a vendor create a product from the front end, the system add the vendor category to the category list in the product?

If I have to write a plugin for that, can you provide a sample code? because I can't file function like getting category object by category name.
Thanks

Best Regards

Hi Jerome,
The requirement is every product created by vendors will automatically set to two categories, the product category and the vendor's category, so do I need to write a plug in for this?

Beside, I don't see the images column in product table, I need the get all the image files of a product, how do I get it?

Best Regards
Scott