Is there a way to import prewritten JSON data into MongoDB when a new user is created but also have it tied to the new user?

I’m building a studying tool that essentially consists of multiple flashcards (in the thousands). I would like to know if there is a unique way or method where the prewritten flashcards can be duplicated and tied to every user who signs up? Or perhaps having the data prewritten inside a JSON file and then upon user creation having it imported into MongoDB with a userID field that the data becomes unique to every individual user. The reason for this is because the flashcards will be using a spaced repetition algorithm and as a result I can’t have one users results be carried over globally for every user. It would need to be unique to that user.

Thanks in advance for any help!

So far I’ve built the flashcard model and tied it to the algorithm however it updates globally across all users. Im havign a bit of trouble with breaking down some of the logic to make it unique to each user.