Gereken cevaplar verilmiş ben ise sizlere hangi platformda program yazmak istiyorsanız hangi dilleri bilmeniz gerek onları paylaşacağım.

WEB:
-> Front-End: HTML5, CSS3 & SASS, JavaScript (AngularJS, Ember.js, Express.js, jQuery, React, Svelte, Vue.js, Flutter)
-> Back-End: PHP, C++, Java, Python, JavaScript, Node.js, Ruby

MOBILE:
-> Android: JAVA, KOTLIN
-> IOS: Swift
-> Cross: React Native, Xamarin, Flutter, Ionic, Corona

GAME DEVELOPMENT:
-> JavaScript, C#, C++, Java

DESKTOP:
-> C#, C++, Python, Java, JavaScript(Electron), PHP, Swift, Red-Lang, Go, Object Pascal
-> Console App, WPF, WinForms, UWP, Other