The only way to resize a smaller photo into a larger, high-resolution image without highlighting poor image quality is to take a new photograph or re-scan your image at a higher resolution. You can increase the resolution of a digital image file, but you will lose image quality by doing so

https://legendofdragoonremake.info/10-ways-to-make-your-images-look-better-with-photoshop/

Proper Depth-of-Field
Put on your longest lens.
Set the camera to aperture priority.
Set the aperture as low as it will go.
Step as close to the subject as you can while still allowing the lens to focus.
Place the subject far away from anything in the background.
Put the focus point on the subject.
Take the picture.