How to get access to specific Data Fields of Data Type Objects within a Collection

For instance:

Collection user has the following fields:

name string

phone number integer

cards List<type of Cards> {

which has field such us :

Card Name : string

cardNumber : integer

Number of Times Used: 10

etc

So now i want to get the card (NAME) and displaying say in a grid view with ... this card has been used (10) X number of times.

This is something simple that seems to be impossible to match/get. i do not understand why i can't just choose from a sub menu the field cardname for instance.