How to save and retrieve data with no physical characters?

I've got a bit of a strange one....my game has no physical characters for now. It combines app with real life. Anyway, I want to store details for players and then recall these details in order to create specific teams. I looked at playerprefs but that doesn't work for multiplayer, I've also looked at Object Synchronization but there's no object so I'm not sure how this would work...

Full disclosure I'm a beginner teaching myself as I go so please go easy on me if I'm being a total idiot! Thanks