WP Multi Network - I'm lost

I know WP Multi Network is a WPMUDEV plugin, but I know there are people here with experience with it and I need help.

I am attempting to set up mydomain.com/state/city/category on my site
such that, the state and city sites operate as their own entities, have editors and contributing writers assigned to each of them.

I have Network configured as subdirectories.
I have WP Multi Network plugin installed - which the plugin has no step by step instructions whatsoever on codex. I am confused about where to start, whether I start in Network Admin or Admin, and what steps to take beyond that.

I do not have mutli-domains installed, for this reason, I am not going to register 50 domain names for each state and dozens more for each cities. I am guessing (hoping) there is not a need to do that.

What I need are step-by-step instructions, (as if I am completely stupid about this, because right now I am) on how to set it up.