I bought a theme for my joomla webpage "joomla 3.6.5". This template uses very handy feature: all articles belonging to a category displayed vertical in a row with an navigation button at the bottom of the list. Tried to copy this layout on anothe Website i can not find the Munu Item Typ: "Category Articles" (Outputs articles from the specified category). How is this Menu item type configured?
You could look in the html-folder in your bought template and try to copy the files there and try to adjust them to your own layout then.
Here's a link where you can see how to add a custom blog layout, it should help to analyze the bought templates structure, so you maybe can change it for your needs. https://www.ostraining.com/blog/joomla/custom-category-layout/