If you already know at least one programming language, you might start with the official Tour of Go. I appreciate its succinct simplicity. Along with a few official blog posts and the standard library docs, it was enough to get me writing useful code.
The spec is far more detailed than necessary to get started with the language. Having to slog through it just to get the basics would have put me off, so I was relieved to find the Tour.
While the documentation page's articles might be useful, I was disappointed with their writing. As an experienced programmer, I found the ones I read immensely boring and disrespectful of my time, because they have a lot of plodding verbiage explaining already-familiar concepts and often restating sentences from just one or two lines earlier. Meanwhile, other ideas are illustrated using (for example) C pointer syntax instead of explaining, which is clear to me, but would likely frustrate someone unfamiliar with that syntax. The authors seem unable to decide who their target audience is.
This is how I learned, I stopped doing the TDD after a while but still a good resource.
https://quii.gitbook.io/learn-go-with-tests