Hello @kartik,
In order to become a “hacker”, preferably white hat (the good guys), you need to learn:
- TCP/IP
 
- Windows systems and how the work
 
- Linux Systems and how they work
 
- Basic Web transactions (HTTP Get, Post, etc)
 
- Security concepts
 
- Command line skills for Windows and Linux
 
- Basic bat/bash scripting skills.
 
- Lots of others, but that should get you started.
 
You can get started with all the skills just follow the blogs of edureka:
What is Ethical Hacking? - Edureka
You can search out for tons of tutorials on edureka:
https://www.youtube.com/watch?v=dz7Ntp7KQGA