What might be helpful is looking at the raw files for Ero Witches at https://madodev.itch.io/ero-witches-downloads. In the "Data"-folder it contains all the csv-files (which I used then instead of txt-files) that are used to import data into the game, it should give you a good idea what you need since that's also what I created before I even started programming the game. You can also import the entirety it into Godot 3 to see how the entire game is made.
Of course, if you want me to photograph all planning notes and detail the entire planning process I did, that would take way too long and is not going to happen.