hi,

see super cell is a china based gaming development company. so if you are interested to work in game development you need to have idea about c#, android technology, Ui OR ux DEVELOPMENT ETC. some of the top online course platform has courses for game development,

Complete C# Unity Developer 2D Course (Udemy)

Computer Science for Game Development by Harvard University (edX)

Game Design and Development by Michigan State University (Coursera)

hope it would help.