Where to start learning react native as i only have experience in java and kotlin

Also, after learning modern JS, as Defman says, you can go to React Native Express.
I learnt a lot there about React Native. After that, write a few small projects. Personally I think "learning by doing" is one of the best ways to learn something. From there, you have to learn your particular libraries and tools, like Redux, MobX, React Navigation, etc. Good luck 😃

I think you should learn modern JS (classes, imports, etc.) before going into React Native. There is a lot of tutorials that cover these topics (search on dev.to and DuckDuckGo/Google/whatever). Once you set yourself up with the modern JS, you can simply open the official React Native documentation. IIRC, it provides a Hello World tutorial 😊