For understanding the basic concepts of Java, follow the link: https://www.w3schools.com/js/DEFAULT.asp
For beggining your Python programming journey, follow the link : https://www.python.org/about/gettingstarted/
For understanding Swift programming language, follow the link: https://www.geeksforgeeks.org/introduction-to-swift-programming/
For learning how to code in Rust language, follow the link: https://www.rust-lang.org/learn
For learning C++, follow the link: https://www.programiz.com/cpp-programming