Aside from knowing the code I need to male an app, what should I do set it up ?, Like the graphics, How can I make up a package?

Question

All that comprises an app aside from relevant code

Answer 1

What do you want to make an app in? Android or iPhone? For Android most probably, you'll need to install android studio. Once you do that, write the application and try to run it in an emulator that you will download later on. After that, you will go to export and generate a signed .apk file. That file that then be copied to your phone and installed.