Hello @kartik,
I would say Edureka have a very good course on certified ethical hacking (CEH). You can checkout there. They have a good foothold in clearing the basics of networking but if you want to learn without a particular course you can go check out their blog.
1)Networking basics
2)Linux
3) Using windows for hacking
4) Cyber attacks
These things should be on.
Tips otherwise basics will not be clear for ethical hacking.
You can search out for tons of tutorials on edureka:
https://www.youtube.com/watch?v=dz7Ntp7KQGA