I am a fresher who only knows only java. can I work on HarmonyOS lib development or else I should know the android development to work on HarmonyOS. Can anyone explain it, please? Where I can learn?
Maybe you could learn from the official docs:
HarmonyOS provides multi-programming-language APIs for you to develop applications. You can choose from Java, Extensible Markup Language (XML), C/C++, JavaScript (JS), Cascading Style Sheets (CSS), and HarmonyOS Markup Language (HML).
The following shows the technical architecture of HarmonyOS.
Setting Up a Windows Development Environment
Here are some codelabs and samples, which may help you better understand the development for key features and scenarios.