…I’m not so sure about the “best practices” bit. You might be better served learning those for yourself. Personally, I think starting with a theme means you miss out on a lot of the chances to learn, especially if you are not experienced enough to be able to spot the mistakes.
Getting Started in the Hugo Docs is a good place to start learning how Hugo works, but beyond that a solid knowledge of html is a basic requirement for pretty much any web development work.
Hugo is essentially just an engine to help you compile the html and css that you write, but faster, so I’d highly recommend a solid understanding of the fundamental technologies of the web; html and css as a minimum.
Hugo is fast, and elegant. I wouldn’t say simple. Logical, yes, but not simple.