I am planning to focus on Go and developing a deep understanding of computer networking. I think with cloud, IOT, increasing importance of cybersecurity, understanding the nitty gritty of networks is going to be increasingly important.
Also, the ZeroMQ Guide has some fun networking concepts. http://zguide.zeromq.org/page:all
Learning the basics of Ethernet would be helpful as well and is one of those foundational skills that'll make it easier to understand various protocols, commands in Linux, etc.