Many games utilize cheat codes and console commands to bypass certain gameplay restrictions. But you won't find anything similar in Resident Evil 3 Remake.
The best alternative is to use a special trainer mod that enables all the game's features in one convenient interface. After you install the mod, all you'll need to do is make all the necessary adjustments to your game beforehand.
This mod allows you to tweak things such as:
There are options for unlimited ammo and invincible enemies, as well as enemy stats and damage modifiers. You can even adjust the item box and fast-forward cutscenes.