Networkers

Training and on-the-job experience are the only ways to become a network admin. Here are some steps:
Learn about how network protocols help to make a network work properly. L1, L2, L3 and L4.
Ethernet - L2 routing, ARP, STP, etc. IP - L3 routing, RIP, OSPF, etc. TCP/UDP - How packets are built and interact with the network. You would then learn vendor-specific tools/commands to make a network work and route packets correctly. At the end of the day, all networks work the same way, the only difference is what commands specific hardware required to make them work. I would also look into how network services like DNS, DHCP, PXE, etc. Work so you will be able to better troubleshoot issues. * To become a sysadmin you have to do following courses.
1- You should complete your graduation
2- Do A+ hardware course (basics in hardware)
3- Do MCITP course (Microsoft Windows)
4- Now you can find a job in sysadmin easily.
5- If you want a higher course you can go for CCNA, CCNP and security courses.

It is very straightforward, but not easy. You should learn in an effective general way like you would study any other subject.
Pick study materials of an appropriate level, do not rush things. For example, pick a book on programming language like Python for beginners, take a MOOC course and practice a lot as you learn new material.
Read a few books on different topics like programming languages, networks, web, OS, databases, algorithms and data structures, GIT. This will set a good base for you.
After you read a few books and practice all that you will know yourself how to continue, what to learn and what's the most efficient way for you.
It's really straightforward, but takes time to become good at it.
Keep learning new languages like every year or so, and master at least one.