Honestly, just use already made modules like ProfileService. Unless your goal is to make a public datastore module someday, or you have a unique scenario that requires a custom datastore, it’s better to rely on people that know what they’re doing and have already built a module.
It will save you lots of time and headaches in the long run. I specifically prefer ProfileService because of how versatile it is compared to other modules like DataStore2.
You also compromise your game’s wellbeing and players’ data if you don’t know what you’re doing.