Q: Can I save a pic as an icon

Hello there, Mummmmmmm7.

It sounds like you're trying to use a photo as wallpaper on your iPhone. The following Knowledge Base article offers how to do that from photos on your device:

Change your iPhone wallpaper - Apple Support

Go to Settings and tap Wallpaper. Then tap Choose a New Wallpaper. Choose an Apple image or one of your own photos. When you select the image you want, you can choose to use it for the Lock screen, Home screen, or both.

Thanks for reaching out to Apple Support Communities.

Cheers.