are photos on the Mac automatically taken up into the iCloud? I want to free up storage

If you turn on iCloud Photos then photos from your Mac are synced to iCloud (if you have enough iCloud storage). If you turn on the Optimize Mac Storage option in Photos > Preferences > iCloud (at the top of the Preferences window) then some or all of the photos on your Mac may be space-saving optimized versions. See: Set up and use iCloud Photos - Apple Support

iCloud Photos is a syncing service. Any photo you delete from a device where iCloud Photos is turned on will also be deleted from iCloud and from any other device connected to iCloud Photos. You can potentially reduce the storage space required on a device by turning on Optimize Storage.

Apple does not currently offer cloud-only storage for photos. If that is what you want or need, you may want to explore 3rd party options such as Google Photos or Dropbox.