The question of whether a person has the option to decide what kind of self they want to have after birth is a complex one. On one hand, there are certain innate factors such as genetics, biology, and early childhood experiences that may shape a person's personality, temperament, and worldview. On the other hand, as a person grows older and gains more life experience, they may also have some agency in shaping their own self through conscious decision-making, education, personal growth, and self-reflection.
In this sense, it could be argued that a person does have some degree of choice in determining what kind of self they want to have, although this is likely to be influenced by a range of factors such as their environment, culture, social norms, and personal circumstances. It's worth noting that the extent to which a person is able to exercise this agency is also likely to vary based on individual differences such as socioeconomic status, access to resources, and mental and physical health.
Overall, while there are undoubtedly some factors that are beyond a person's control, it's also true that individuals can play an active role in shaping their own identity and self-concept over time.