Moved everything to iCloud but mac still says storage is full

iCloud is a syncing system, not an external storage system. If you delete them from the device/computer  they will be deleted from iCloud. For the computer, go to Photos/Preferences/iCloud and select Optimize. That will reduce the space required for Photos by about 90% when fully effective.   

You can also turn on Optimize Storage for other files. See the 'Store your files in iCloud and save space on your device' section of the article below.

Desktop and Documents files to iCloud Drive.    

For what you want to do, you need a different cloud based solution such as Dropbox, OneDrive, or Flicker.

I've moved everything to iCloud but mac still says storage is full. What can I do?

There really isn't a "move to iCloud" option.

What are you syncing with iCloud? Photos? iCloud Drive?