How do I get started with QT application development?

I need folder and file setup help. I also need to know what the best way to learn qml, c, c++, json is.

Most IDEs with Qt support, e.g. QtCreator and KDevelop, have application templates that get you started with a project structure and common files.

For learning QML you could have a look at the YouTube series published by Qt specialist at KDAB

Thank you! Will watch the video and come back if I have questions.