i want to start coding game cheats but dont know what to do exactly and where to code

Answer 1

Where to start?

STEP 1:
Have deep interest in that particular game. Play it often. You'll get to predict how major things work

STEP 2:
Be very proficient in ALL of these languages. Java, Smali, C++ and little assembly.
Decompile the software using tools like ghidra, jadx and modify the source code. Recompile and that's all

STEP 3:
Incase the game is online, you have to know JavaScript and some networking. I'll suggest you get Wireshark to trap fetch/xhr requests and their likely payload so you can bypass some APIs therefore making and moding the game

LASTLY
make sure the game allow you to mod it