This chapter talked about many interesting Go topics, including compiling Go code, working with standard input, standard output, and standard error in Go, processing command-line arguments, printing on the screen, and using the logging service of a UNIX system, as well as error handling and some general information about Go. You should consider all these topics as foundational information about Go.
The next chapter is all about the internals of Go, which includes talking about garbage collection, the Go compiler, calling C code from Go, the defer keyword, the Go assembler, and WebAssembly, as well as panic and recover.