Not to discourage you, but two weeks in seems a bit early to be worrying about online functionality. If I understand right that you want to make a sandbox, I'd focus on creating that first :-)
I'd guess step 1. is saving and loading the games you create locally, step 2. getting a server and making an API to send the save files back and forth... I'll admit I only have web app experience with sending relatively small files like xmls, it's probably more complicated for online games.
