whoever gets it, a friendly suggestion. After you do the tutorial (which helps teach you the interface, but not the game itself), play your first game as a count in Ireland. Ireland is called 'tutorial island' for a reason, you're far away from warmonger countries, England is too busy to invade you, and Ireland is fragmented into several small counties easy for the picking, so you get to learn in baby steps and slowly get into the whole dynasty thing (marrying your kids for alliances or future claims, etc).
It's all about claims in CK2. In Ireland for example, become a duke and now you have claims over all the 'de-jure' counties in it (so, usually you can just 'ask' those counts to become your vassals without even a battle).