Currently, making a 3D model requires much more information to process in a computer than most 2D image files (JPG, PNG, etc.). 3D models are a collection of points in 3D space, so they have a length, width, and depth. When you take a 2D photo, you’re only capturing the length and width.
There is no software that exists that can take a single 2D image, like, for example, a family photo, and produce a robust 3D model.
With that being said, Sketchfab does not have resources to take 2D images and make 3d models, however, you could always seek out a 3D developer to hire and build your model for you.
Likewise, there are a few other options for creating 3D models you might like to explore:
• Photogrammetry is the process of taking multiple 2D images in 3D space and using 3D modeling software to combine that collection of images into a 3D model/product. If you’re interested in this option, I’d recommend checking the 3D scanning resources in the 3D Scanning guide.
• There are some 3D modeling programs out there that can help you sculpt/create 3D models out of single 2D images. They do require a bit of time and patience but the results can be what you’re seeking to do. A good example is Smoothie-3D.