If you performed an iCloud backup of your old device then you need to sign in with the same cloud account on your new device and choose restore from backup and all your photos will be restored but sadly your videos will not
Yes I know that. I restored my new iPhone photo library from iCloud, but all these photos are unfortunateli not in the full resolution. I dont know, if my iphone is still downloading the photos in full ress in the background or I dont know what is happening. I have a 128 gb version and I would like download all my photos in full ress. Thanks