Each website kit is packaged up nice and neatly and all template files are named accordingly. You will get a quick setup PDF guide that explains how to load the template files onto your WordPress website.
Most digital agencies at some point will purchase a WordPress theme for their clients. It is a great way to speed up the creation and development process. Bare in mind that these themes come with a specific look and feel as well as functionality.
Before I start building any website I sit down and map out the process, determine the functionality of the site and start thinking about the layout of how everything will look and function on desktop as well as mobile.