Kit55 comes with a sample site that is kind of self-explanatory but you can download any plain HTML theme from the internet and use it as the base for your own

Kit55 comes with a sample site that is kind of self-explanatory but you can download any plain HTML theme from the internet and use it as the base for your own project. We do work a lot ourselves with tailwind templates, as there are a lot of sites out there that provide functional blocks (e.g. https://tailblocks.cc https://tailblocks.cc) that can be easily made into HTML template files (Kit55 building blocks).