Hello, how are you doing? Hope you well

I'm a beginner with game development (took a couple of courses about Unity), and I just learned the basic things such as making a few scripts to move the player around followed by a camera etc. My main goal is to create a simple 2D game for Android, I have achieved some sort of game prototype but for Desktop and I was wondering, all the stuff that I'm making through tutorials and courses that are not particularly oriented to android are going to be useful for me? I mean my doubt is that if I can create the game as I want and then turn it into android or I need to follow some rules from the beginning?

thanks

You can make Android games in Unity without much additional knowledge, but you don't just change it to Android at the end - you will want to be testing on Android as you go along, to make sure the input works, to make sure it renders well on the device, to see how it performs on Android as opposed to desktop, etc.

1 hour ago, JS_means_JackSparrow said:

I have achieved some sort of game prototype but for Desktop and I was wondering, all the stuff that I'm making through tutorials and courses that are not particularly oriented to android are going to be useful for me?

Of course  You are still gaining experience with the Engine and how it works by making any kind of game for any platform. Those tutorials might not teach you something you can run to your game and implement now, but it helps lay a good foundation of knowledge for the basics of game development (and how the engines work) that will help you when it comes time to making an android project. Truthfully there are so many tutorials for developing for Android using Unity. The joy of these engines is that you can learn something new in no time by Youtubing a tutorial on a specific engine feature (depending on how advanced your getting here), as well as working with documentation. My ONLY advice to you about engine development is to stick to one engine, don't worry about the Unity vs Unreal vs CryEngine crap and learn Unity (if that's the one you want) as each of these Engines differ from each other some how and you will have a very hard time making any kind of game if you spend your time learning engine features from each engine. 

Short Answer: 

Yes, you will still learn a LOT from your project experience when it comes time to develop for Android.   

I think the controls in Android are different, you cannot use input.getAxis("horizontal") I think.