You can do this using an aperture of around f/2.2, shutter speed around 1/250 and an ISO to balance — start with 320 and tweak if required. Bear in mind your settings will depend on the ambient light you have at the time, so there’s no one-size-fits-all exposure setting.

Use shallow depth of field to make the subject stand out and soften the background. I often shoot on f/2.8 or f/2.0. This also allows more light into your camera. The higher your shutter speed, the less light will enter your camera. I recommend starting with shutter speed 1/100 and then raise it until you get the look you desire.