Uploading iCloud on new iphone

See the three options in Transfer data from your previous iOS or iPadOS device to your new iPhone or iPad - Apple Support

If the new iPhone is already set up, you will need to erase it. See the following from Use iCloud to transfer data from your previous iOS or iPadOS device to your new iPhone, iPad, or iPod touch - Apple Support

1 - Turn on your new device. A "Hello" screen should appear. If you've already set up your new device, you need to erase it before you can use these steps.* 

* To erase your device that's using iOS or iPadOS 15 or later, tap Settings > General > Transfer or Reset [Device] > Erase All Content and Settings. On iOS or iPadOS 14 or earlier, tap Settings > General > Reset > Erase All Content and Settings. This erases all data on your device. After you erase it, your device restarts and the "Hello" screen appears.