My goal is to be able to do all kinds of operations on server and manage it. I am not sure where and how should I approach towards this goal.
Also, What are the skills that a devops person should have?
Learn how Linux works, I would suggest you to do Linux From Scratch (LFS) so that your fundamental are clear.
After that you can see @fibric answer so you will get some idea about DevOps.
Found a great post about DevOps in the JavaScript/Node.js eco system.
@fibric highlighted the main points. I would just put the spotlight on the most important -from my own point of view - points (already in his list):
Sébastien Portebois
Software architect at Ubisoft
Denny Trebbin
Lead Fullstack Developer. Experimenting with bleeding-edge tech. Irregularly DJ. Hobby drone pilot. Amateur photographer.
Good question. It's a marriage of two IT departments, development and operations. Becoming really good means to learn tools and methodologies of both worlds.
Communication is a big thing.
For short, learn to automate and develop a culture of experimentation
I have no experience with paid all-inclusive courses. But here are some sources I am observing from time to time