The poster did not clearly state what the issue was, or how the size of their hard drive was related to their iCloud issues.
MessiahMusic wrote:
The fact is that the default setting on the new OS sets everything to go to the iCloud, which only has 5GB available for free, and for those of us with phones, chances are that is already full of photos etc. Thus, the very moment you try to save anything the iCloud is full.
The new OS does not set everything to go to iCloud. If you are specifically referring to Desktop & Documents, you may have simply overlooked the page where the question as to whether you want to use it or not came up. The option to not use it isn't very prominent, so it is easy to do. But it is just as easy to turn it off if you don't like it:
When you turn off Desktop & Documents Folders, your files stay in iCloud Drive and a new Desktop and Documents folder is created on your Mac in the home folder. You can move files from iCloud Drive to your Mac as you need them, or select all of your files and drag them to the place you want to keep them.
- From your Mac, go to Apple menu > System Preferences > iCloud.
- Next to iCloud Drive, click Options.
- Deselect Desktop & Documents Folders.
- Click Done.
If you turn off iCloud Drive or sign out of iCloud, you have the option to keep a local copy of your files that are in iCloud Drive. Whether you decide to keep a local copy or not, a new Desktop and Documents folder is created in your home folder. If you choose to keep a local copy, your files in iCloud Drive are copied to a folder called iCloud Drive (Archive) in your home folder. Then you have the option to move any files that were in your iCloud Desktop and Documents, back to your new local Desktop and Documents.
From this support article: Add your Desktop and Documents files to iCloud Drive - Apple Support
If you are using iCloud Photo Library, that is also your choice. I don't use iCloud Photo Library - never have. So, if you have photos in iCloud, it is because you chose to turn on iCloud Photo Library.
You must be signed into iCloud for some services, but you have complete control over what parts of iCloud you use.
If you want to save a document in iCloud Drive, then make sure you have enough storage to do so. If you are using iCloud Photo Library, it is highly unlikely that the 5GB free that you get will be enough to house that library as well as anything else you might want to store on iCloud.
Here is an overview of the various parts of iCloud that may clarify how it works for you: iCloud Deconstructed | Communities
Cheers,
GB