I saw on the Internet that photos taken by others can blur the flowers in the foreground and the flowers in the background at the same time, but the main part of the portrait is clear and beautiful.

The main factors affecting the background blur are: aperture, focal length, the distance between the subject and the background, and the distance between the camera and the subject.

In order to make the background blur effect good, use a large aperture and a long focal length, keep the subject away from the background, and keep the camera as close to the subject as possible.

The foreground you are talking about is actually the same as the background, mainly to distance the subject from the foreground.

For example, if you want to take an outdoor portrait, the model stands in the middle, the trees in the distance can be used as the background, and there are grass or leaves in the foreground near the camera. Use aperture priority to increase aperture. If it is a zoom lens, try to use the telephoto end and focus on the model's face, so that the leaves and grass in the foreground and the trees in the background are blurred and the model is clear.

This is to use the shallow depth of field of large aperture to make the foreground and background out of the depth of field.