Can I transfer photos and some music to iCloud to free up memory on my iPhone

You can potentially free up some space by turning on iCloud Photos and the Optimize iPhone Storage option in iCloud Photos. See information in Set up and use iCloud Photos - Apple Support

Note that 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.

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.