What are sources you use to learn completely about a programming​ language other than Sololearn ?

Question

Sololearn is the best but other sources would be very helpful. If you're a developer then
1. how do you get started, help me out.

Answer 1

Youtube and for apps you can refer the code
https://code.sololearn.com/W8Lx47msLgTJ/?ref=app

Answer 2

Tutorialspoint
Stack overflow
YouTube tutorials