Where to start with kotlin?

Hello. I am seriously thinking of learning kotlin. My goal is to make couple of mobile applications hopefully are used by everyone who owns a mobile device.

I am happy to see that kotlin can be used on many categories. Console, desktop, backend, mobile etc. But at the same time I don't know where to start? Perhaps the console is a good starting point? Then to mobile development,

Note: I do have a background experience in programming with c#.

Please advise me and thank you.