for someone who has zero knowledge of networking, looking at those pics - WOOOOW!!
networking seems to be a hit or miss for people, some people find it very logical and "easy" while others seem convinced it's black magic.
networking basics is rather easy, the problem is complexity that gets added when you scale. (although i doubt you would reach that point in a homelab though).
You seem convinced it’s not black magic, so recommend a book/mooc/resource that’ll prove it. :-P
And this one will fill out your knowledge on the routing side, although it is rather dry: https://www.amazon.com/Network-Routing-Algorithms-Architectu...