How to edit a regular photo so that it looks like this? Or how to make an image in a vector style from an ordinary photo?

Question

Image processing

Answer 1

Put a regular photo in the background and start tracing using the illustrator tools: Pen Tool or Curvatore Tool and do a few more simple but routine actions.
This is painstaking work (if you want to get a good result).

Answer 2

www.popartstudio.nl
Select Roy Lichtenstein effect
You can also google this effect.