How to properly debug a disassembled app in android studio?

Question

Android

I welcome everyone!
Due to the duty of the profession, there was a need for reverse engineering of the android application. Alas, I'm new to android development, so please be understanding))
So, step by step:
1) I took 2 versions of the application: 1st from the play market (installed on the phone and assembled an apk from it using a lucky patcher), 2nd version was taken with pdalife.
2) Decompiled in several ways - dex2jar + jdgui + apktool, akptool online, dex2jar online.
3) The received files were gorzed in android studio, I tried to run it on the built-in emulator, but I got misconfiguration errors, crashes, and other fear and horror.

Also, when importing apk directly into android studio via Profile or debug apk, the application crashed on the emulator.

Actually the question itself: ̶ch̶t̶o̶ ̶i̶m̶e̶n̶n̶o̶ ̶i̶ ̶d̶e̶l̶a̶yu̶ ̶n̶e̶ ̶t̶a̶k̶ considering that apparently I’m doing everything wrong, please tell me how I should run the application on the emulator to modify it again and

debug with understanding, and do not throw faeces of all types and sizes)

PS Thank you SO MUCH in advance for competent and useful answers :)

Answer 1

Reverse engineering, in itself, is not an activity for beginners. The decompiler gives you sources, and if the developer took care of protecting his application, then they are terribly badly readable (obfuscation).
At the same time, the IDE (Android Studio) to build the application, these sources are not enough, some more information is needed that you do not have. It needs to be added by hand, analyzing the received sources.
Maybe, of course, there is an easy way to get the source code that is being built, but I personally don’t know of one.