I have modded my physical copy of Fates. It might seem daunting but it is actually pretty easy. As far as I know you can't give yourself infinite resources, but you can give yourself 99 of every resource and then hack in more when you run out. I don't know exactly what you are trying to do, but I'll list some tools.
FEFTwiddler: Fates Save Editor. Lets you give yourself gold, resources, weapons, and more. Also lets you revive characters, obtain skills you normally can't get (like Inevitable End or Staff Savant), change stats. Basically, you'll use this for simple cheats.
Paragon: Fates GameData Editor. Enables you to add/change game data like weapon stats, class data, and character data.
Gamebanana Tutorials: These will show you how to use Paragon and how to load mods with Luma.
Save Manager: Lets you export your save data so you can make changes to it with Twiddler. Also lets you import your changes so they show up in game.
Also, you'll need to dump your game's romfs folder. However, I recommend doing this with a ROM because it will take a long time to dump your physical copy. Dumping the ROM with Citra will only take a few seconds instead.
I can walk you through it as well if you are having trouble with it.