Hello jillfromlaytonsville,
With regards to duplicate photos on the iPhone, you may find helpful steps for that process here: Find and delete duplicate photos and videos on iPhone - Apple Support
1. Tap Albums, then tap Duplicates below Utilities.
Duplicate photos and videos appear next to each other.
2. Tap Merge to combine the duplicates, then tap Merge [number] Items.
Merging combines the highest quality version and all of the relevant data across the duplicates, and keeps that one in your library. The remaining duplicates are moved to the Recently Deleted album.
If you don’t have any duplicate photos or videos in your library, the Duplicates album doesn’t appear.
Note that this will require the iPhone to be on the newly released iOS 16, and then it may take some time after updating to have the Duplicates album appear in the Utilities section of the Photos app. You may try connecting the device to power and leaving it locked overnight, which may help accelerate the process.
Regarding files uploading to iCloud, if you've made edits to an existing file, then it will just upload the edited version and shouldn't be a separate file (unless you opt to create a duplicate manually).
Cheers.