I have downloaded and installed the DLC Freedom Cry but how can I play it? Is there a location?
In the top right box of the main menu
If you used Steam to purchase the DLC, you might have to redeem the item in-game manually.
First, click right on the Black Flag game library in Steam, click "View CD key", and copy the Freedom Cry key to the clipboard.
Then start the game and go to "Extra content", click the "Redeem" button at the top right, and paste the key and confirm.
Finally, restart the game and you should be seeing a picture featuring Adewale in the top right of the main menu (possibly sharing the space with Adeline, another character unlocked in a DLC).