Welcome to iMore! Do you have your old device? If so, you could back it up now, then set up your new device.
If you can't do that, then set up your new device as new and start fresh.
Go to iCloud.com on your computer and log in. You can see there if there is a back up.
1. Are you signing in to the new iPhone with the same Apple/iCloud ID as the previous iPhone?
2. If you still have the "old iPhone", can you not create an iCloud backup right now and then try to restore that backup to your new iPhone?