I want to became a good app designer what i want to do?

Answer 1

I guess you are asking what you should do to became an app designer. First of all it depends in which platform you want to run your app. Like if you want to run your app in Android than you can go for Java for background designing and XML for fronts and you can use Android studio to design your apps

Answer 2

It's always a good idea to practise by doing "practical" coding. Look for some challenges in the internet!