Delete a photo
A delete can remove the photo from online storage and other devices too. Keep a separate copy of any photo you want. You may not be able to get a deleted photo back.
Take a test photo of a blank wall. Use just that photo here. Do not try this with a photo you want to keep.
Let us go through this together, one little step at a time.
Tap each step once you have done it. Nothing is timed. Pause and check before sending, deleting, or agreeing to anything.
Apple usually keeps deletes for 30 days. But if iCloud is over its space limit, you may not get them back. Google Photos keeps backed-up photos for 60 days. Most unbacked photos stay for 30 days. Other apps differ. Read the time left in your app.
Sync can delete other copies too. Emptying the trash can make a delete final. When the time runs out, you may not get the photo back.