Go specification. For detailed descriptions of Go keywords, I recommend reading the official Go specification. This document is not exciting, but it is excellent in every other way.Go Specification: golang.org
Some notes. Operators are another key part of the Go language. These include the plus + and other arithmetic ones. These operators too are built in.
In Go we find a newer, well-designed set of features. The Go compiler itself is an impressive technical feat. A Go developer will do great things in the world.