There are a lot of ways to unlock special content in Mafia: The Old Country, including pre-orders, linking your 2K Account, and more. So when you first log into the game, you'd expect to see all those bonuses - but you're going to need to be a little more patient if you really want to join the Family...
Different content, even from the pre-order, will only unlock as the story unfolds:
Explore Mode unlocks after completing the prologue.
This mode is found in the Chapter Replay menu, right at the top.
Wardrobe and Charms start inside of Chapter 1.
Some Outfits are unlocked within the progression of the story, other Outfits are only purchasable with denari as the story progresses.
Outfits from your DLC are in your wardrobe right away.
Charms unlock once you find your first one in the story, then you can access any from your DLC, too.
Knives are unlocked in Chapter 2.
The stable for Horses will be unlocked during Chapter 4.
The garage for Cars and weapons lockers through the game for Guns are unlocked at Chapter 5.