I need to create storage on my iPhone. I have purchased storage on iCloud. How do I ensure that all of my photos are in ICloud? Can I delete photos of my iPhone to create storage and still have them saved in iCloud

Okay, lots of questions or comments in your post so let’s pick it apart.

If you need to create storage on your iPhone, do remember that your device already comes with storage that cannot be altered or changed.

About storage on your device and in iCloud - Apple Support

How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

Manage your photo and video storage - Apple Support

To ensure all of your photos are in iCloud, be sure you’re using iCloud Photos - Set up and use iCloud Photos - Apple Support.

Last question/comment, no you cannot delete photos from your device to create extra storage. You see, when you store the photos in iCloud, folks think they can then remove the photos from their device but iCloud wasn’t designed that way. It’s a syncing service that basically syncs your photos/videos across all of your devices.

Delete that photo from iCloud, and it will be deleted everywhere and gone for good.