Want to write online service for board games as my diploma in University

I`m big fan of board games, and when professor ask what I want to write as a diploma, I make decision fast - service for online board games.

Now I have some questions, which I don't know how to implement correctly:

First of all this is architecture, how correctly implement state machine and in the same time make this service scalable for adding different types, like card games, miple games and so on

Second is how work with data base and store all this data like cards actions, or more complex logic

If you know some resources, except of AI where I can read and research about this theme, will be glad