You can find Clans to join or create your own Clan using the Call of Duty App.
Download the Call of Duty App to your device through your device's app store.
Once the app is downloaded, log in to the app using your Call of Duty account.
From the menu, select FIND & JOIN CLANS.
In FIND & JOIN CLANS, you will find Clans that your friends are in, Recommended Clans, and section where you can create your own Clan.