Programming is must for all especially for Computer Science Students. Here are some good platforms from which you learn all the concepts. For Beginners I suggest to go with Sololearn for all languages.You can check the link below.
These are some good Compilers/IDE's for different platforms
C/C++ :- Codeblocks,Turbo c++.
Java :- Netbeans,Eclipse.
Python:- Python IDLE,PyCharm.
TIO :- Try It Online which supports 400+ Languages.
Very Useful Intellij,Visual Studio Code,Visual Studio for majority of the languages.
Select your language based on your requirement and start learning through best documentations.
Most of the members start with this as it is very simple and easy but not mandatory to start.
Mostly used language for competitive programming as it supports Object Oriented Concepts with simple syntax to code.
Very Useful Platforms with great benefits.
Programming Hub is an app to quickly access programming manuals for more than a dozen different languages.
Tutorials Point originated from the idea that there exists a class of readers who respond better to online content and prefer to learn new skills at their own.
Codecademy is an online freemium interactive platform that offers free coding classes in 12 different programming languages.