phone says not enough storage for backup
so phone says not enough storage for backup but I've only used a minimal amount
The simplest explanation for that error is that you are out of iCloud storage.
Per Apple: If you get an alert that you don't have enough iCloud storage space to complete the backup, follow the onscreen steps to upgrade your iCloud storage.
The free 5 GB that is provided with an Apple ID isn’t all that much storage. It’s not usually enough for a backup, if you have much of anything stored on your iPhone.