How to implement an Abstract factory + App.config C#

i am new to C#.

I am working on a user maintenance console application. Currently I am storing my data in XML Files. I do not have to implement a relational database but I have to design my application in a way that the console application itself is completely unaware of the persistence backend and have to use the abstract factory pattern to do so. I have to create a AbstractDBFactory class which determines based on the configuration in App.config which DBFactory class is instantiated. Also a XMLDBFactory class has to be created which reads the file details from the App.config as well.

I am struggling on how to tackle this problem. I was hoping someone could give me some tips to help me get into the right direction!