Some Learning PlatForms
For Coding/Programming Knowledge
GeeksforGeeks
W3Schools
Sanfoundary
TutorialsPoint
Javatpoint
Guru99
For Competitive Programming
Hackerrank(Specially for Beginners)
CodeChef
LeetCode
Hackerearth
CodeForces
Open Source Contribution
Github
Bitbucket
Official Documentation
Java(Oracle)
Python
SQL
JavaScript
Linux
C
Git