TL;DR

Read Chapter 5.4 in The Go Programming Language by Alan A. A. Donovan and Brian W. Kernighan. In just two pages, the original designers of the language explain the essence of Go error handling.

The book was published in 2015, before the Go standard library added additional convenience functions in 2019. So, also read this blog post: Working with Errors in Go 1.13.

For some examples, check out: https://tour.ardanlabs.com/tour/error-handling/1
You can also skim through the “Extra reading” section, but keep in mind the age of those posts.