Using actors to hold individual statistics, is your best choice for storing individual card information.
How ever without more information on exactly the kind of math you need the BPs to do, there’s not much more useful information to give out.
Other than that, You can create a random number through using the command Random Integer in Range.
You can apply complex math’s much easier by using variables, macros and functions.
You can make a base class for all your cards, with the BPs required for interaction, and make children off of that base class.