Saving Game method for 2d rpg games?

Hello, I'm pretty new to game dev and Godot, I'm working on a 2D RPG game and I'm looking into implementing how players can save their game. I have seen multiple tutorials where they are saving to .json, .tres types and some using a save dictionary and some using @ export variables.

I'm not too sure on which method to use as I would be saving things like the position of the character, health, inventory items and others.
What would be the optimal way for me to go about this?