Can You Turn a 2D File or a Photo into a 3D File?
Unfortunately, we can't make a 3D print out of an image file, a PDF or a photo. Before you can 3D print anything, you always need a 3D model. A 3D model is a virtual input that a 3D printer needs to print an object.
There are free apps, like Qlone or Smoothie 3D, that can transform photos into a 3D model. Please take note that a successful outcome for these apps strongly depends on the complexity of the object/photos.
You can also get a 3D file through 3D scanning, designing something from scratch in your favorite 3D design tool or hiring a 3D designer to do the modeling for you.