How to become a system administrator?

Question

System administration

Hi all! Next is a long read, because I want to describe my question in as much detail as possible.
So - I'm a schoolboy, you can say a graduate - now my last 11th grade will begin and the realization has come that this is the end of that straight line along which I followed the orders of my parents, teachers, etc. Now I have to choose what to do next. And it's hard for me to choose.
In general, everything that is obvious to me, that is, what facts are spinning in my head:

• You need money to exist.
  
• The most guaranteed way to get money is to go to work
  
• Only those who "fumble" are hired
  
• In case I don’t dare to do anything else, for example, create my own business, I need to choose a profession that would be pleasant ...
  

...namely, to choose, because I am one of those people who need to build a foundation on which in the future it will be possible to build a house, and then you look and decide to do something else. So the bottom line is that I'm not against getting new knowledge. I am in favor of acquiring some theoretical knowledge on which everything related to my profession is built, constantly learning. But I will constantly improve for a long time only in one direction, before starting to move in parallel in another.
In general, coming to the point, as the name already implies - I want to become a system administrator.
Why I chose this profession:

• I am imbued with love for my (perhaps not really existing) ideal: I imagine a system administrator as a dude sitting behind a throne, setting up servers, computers, networks ...
  
• I like computers as an ordered system where I want to study everything, understand how it works, while becoming a development in this area
  

Now I have a question, but how to become one. All I've done so far is:

• I studied and continue to study Linux
  
• Configured and debugged all sorts of different servers (web, smb, ftp, mysql...)
  
• If something broke, he treated it with Google and smoking mans. If no solution found, post bug reports
  
• Later, with Mikrotik, I discovered networks and began to study protocols, systematizing them along the "axis"
  
• A bit kodil
  

In short, I toiled with garbage, trying to try everything in practice, remembering the theory.
Well, now to the point - what I want to hear here - how can I become this very system administrator:
1) I do not quite understand if there is something in common between a network manager and a system administrator. My guess: in the right way, everyone does their own thing, but in practice, the switches are configured and the servers are served by the same person.
2) How can I get the necessary knowledge? After reading on the Internet, I realized that only self-education. But in contrast to years of propaganda from everyone around that without an institute, I will not get a nuclear theoretical base.
3) The previous question was about how to gain knowledge. And this one is about how to prove them? I understand that it is necessary to obtain certificates according to the requirements. For example from known to me - the certificate of Mikrotik. The same is true for everything else. Plus a diploma - as an indicator that I went through fire and water.
4) And what if tomorrow the system administrators are no longer needed. They will be replaced by robots, for example. Futuristic, but purely as an example.
5) Be sure to write that with such an attitude I will not become any system administrator, but the truth is that I simply do not know which path is right due to a lack of life experience and a bunch of opinions from all sides. All I want is to do what I love: poking around in lines, networks, etc., and also getting a livelihood from this.