Need Help with Finding Functions

[GamiGG]

Hello, I've been trying to cheat in a game called Memoria Freese recently and have been trying to use Game Guardian. Since I'm an amateur at this I tried just finding addresses for items and changing the values, but that didn't work. Sometimes the search would end up empty, and other times changing the value of the address I found did nothing. After trying that for a few hours I eventually found someone who had done something similar for other games but had success, he said that you need to use the address to find the function behind an action in order to get the item from the shop. I searched for many tutorials on finding functions but they were all for cheat engine on windows, and they seemed to be very different scenarios to the one that I am in. I haven't been able to get in contact with the guy since then, so I thought I should ask here. Can anyone help me with this?

Also if anyone has the time I'd love to hop in a chat and learn more about this, I'm actually trying to get into it.