Google has published starter guide for SEO beginners. It describes what SEO is, Why is it for and How it can be implemented. Purely it is structured for beginners.
It is an inclusive guide for the practice of on-page optimization for those unfamiliar with the subject. But it has not covered much about off-page optimization. As it for beginners, it is better to provide more details about off-page SEO.
On-page and off-page SEOs are two eyes of SEO. In order to succeed in online business, it is must to implement both on-page and off-page optimizations.
To put in nut shell, this guide will surely help those persons who are about to start their online business. When it comes to promotion, the off-page optimization plays major role. Hence I recommend Google to give off-page optimization in detail.
Google SEO Guide : https://developers.google.com/search/docs/fundamentals/seo-starter-guide