what's the best free website to learn coding ?

For what platforms? What kind of apps? What are your goals?

Hi, my name is yacouba I’m from Niger , i suggest you to try www.openclassrooms.com let me known what you think later if you find time to leave it for replay to me! Excuse for my English but but I don’t speak fully

There are a few. Apple Developer forums (here), StackOverflow, and Google. That's assuming Swift or Objective-C on any Apple device. Just like KMT said though, what do you want to do on what?