To capture portraits, you'll need a so-called portrait lens. Portrait lenses are light sensitive and often have a small aperture number, such as f/1.8. This combination ensures a natural background blur, making it seem like the person is being separated from the background. Portrait lenses vary in focal length, the required focal length is up to the photographer and how much compression and background blur is desired. Pay attention to the mount when purchasing a portrait lens. Check if it's suitable for your camera.