I have an iPhone X with 256 GB of storage, which is a lot. However I have very little iCloud storage. How can I save everything that is on my phone, to my phone, and then clear iCloud and wipe it clean? I know that iCloud provides a backup and a way to see things from different devices, but I won't lose my phone, and I can probably find a way to upload single files to iCloud.
I have tried not letting the device upload to iCloud, but the AppleID and iCloud section on settings is grayed out (parental controls) and when I tried it on laptop it just cut off the connection without saving to the device or clearing the space on iCloud.
How can I fix this?