This is a strong position for the SUN.
It will show us an active, open, noticeable person. These are truly little suns, as if they are shining, they are natural in their manifestation. It is impossible not to notice such a person - the inner light that emanates from the person. Able to infect others with their enthusiasm.
Such a person is self-confident, often becomes a leader.
Certainly, to a large extent it depends on which sign the Sun is in, but still he is bright, you can feel this core, this will of a person. Even if the Sun is struck by a large number of tense aspects, a weak sign for itself, the Sun in the first house will always strive to manifest itself so that it is noticed.
Of course, if the Sun is in the Fire Signs, it is easier for a person to come forward, to feel like a leader. The Earth simply believe in what they are doing, know their strength.
The Sun in the 1st house also indicates a close connection with the father. Since the Sun is a masculine planet and it is associated with the figure of the father, his influence in a person's life is high. He may guide, be a kind of ideal, a reference point for a person.
For a woman, this is also the image of a husband.
Of course, the cards can be different and there may not be a close connection with the father, but the father is important, even with tense aspects of the Sun and Saturn. Here we look not only at the tense aspects to the Sun, but also pay attention to the involvement of the Sun (the boundaries of the Zodiac signs in which the Sun is located are fully included in the house). Such a position may also speak of the difficulty of a person's self-realization.