A family of Microsoft word processing software products for creating web, email, and print documents.
How are you printing these?
An Avery cardstock template?
When you flip the card, are you flipping on the long side or the short side? (Do you want the text on both sides oriented in the same direction?)
This is not going to be simple.
The easiest method is likely going to be a Mail Merge with your questions and answers stored in an Excel Sheet.
Mail merge using an Excel spreadsheet - Word
Here is a search revealing a number of suggestions: https://duckduckgo.com/?q=create+flashcards+using+Word&t=ffab&atb=v248-1&ia=web If you look at these, and need help, write back with a link you think is closest to what you want to od and what you have tried.