Hey there gokartmozart,
Thanks for reaching out to the Apple Support Communities. Just to confirm, are you using one of the default wallpapers from the previous iOS version, or are you using a photo from your Photo Library? If using a photo from your Photo Library, are you able to locate the photo in the Photos app?
If you are, then check out the steps listed in the following resource for the best steps on customizing your Lock Screen: Personalize your iPhone Lock Screen - Apple Support
Add a photo to your Lock Screen
You can add a photo to your Lock Screen by selecting one from your photo library or letting iPhone intelligently suggest a photo that complements your other Lock Screen settings.
1. Touch and hold the Lock Screen until the Customize button appears at the bottom of the screen.
If the Customize button doesn’t appear, touch and hold the Lock Screen again, then enter your passcode.
2. Tap 
at the bottom of the screen, then choose one of the photo options (Photos or Photo Shuffle) at the top of the screen.
3. If you choose Photos and want to create a multilayered effect, tap 
at the bottom right, then choose Depth Effect.
Note: This option may not be available for all photos. Layering is not available on wallpapers with widgets. The multilayered effect is available on supported models. Layering is available only on images with people, pets, or the sky, and isn’t available on every image in those categories. Layering may not be available if the subject is too high, too low, or obscures too much of the clock.
4. To reposition your selected image, pinch open to zoom in on it, drag the image with two fingers to move it to the position you want, then pinch closed to zoom out.
You can also swipe left or right to try different photo styles that include color filters and fonts that complement each other.
5. If you choose Photo Shuffle, you can preview the photos by tapping 
, and set the shuffle frequency by tapping , then selecting an option below Shuffle Frequency.
Tip: Alternatively, you can add a photo directly from your photo library to your Home Screen and Lock Screen. In the Photos app 
, tap Library, select a photo, then tap 
. Scroll down and select Use as Wallpaper, tap Done, then choose whether to show it on both your Home Screen and Lock Screen.
Let us know if that's able to help.
Take care.
