If you don't have any experience and programming background you should start with C/C++ to learn basics, data structures, algorithms etc. Then you may continue with C++ or move to different language - for example, C# or even F# if you like functional. With C# you can write mobile apps for both platforms using Xamarin. Please don't start with JS, actually try to avoid JS as much as possible because that's not programming language - but that's my opinion.