Best way of saving data?

Hi, I’ll try and keep things short.
I’m trying to learn lua and what I basically want to do is have a system that allows players to add a numerical value (For example, say /rep NAME 1 and then have the server add 1 to the total value)
I have a basic understanding of how languages work, I don’t normally result to asking for help but finding detailed explanations on lua isn’t easy.

Currently I have

file.CreateDir( "repsave" )

to create a save file in the data folder on the server.
Would this be an appropriate way of saving what I am trying to do or is it better to use SQLite.

If anyone could point in the right direction of how I can do this that would be great.