How does one go about learning physical network setup and maintenance?

I have an IT background in programming. I have come to realize I prefer blue collar physical work to sitting down and programming. I don't want to throw my IT background because I make good money.

I was thinking of trying to get into physical network setup both LANs and WANs. Maintaining servers physically and perhaps as a sysadmin too, but for lots of servers. If something goes wrong physically fix it and stuff.

I know in the past Cisco was big. Not sure if this is still the case? Maybe it is some Chinese company now.

How can i go about learning this in my 30s?