Childhood social and personality development occurs as a result of the combination of social factors, biological maturation, and the child's perceptions of the social environment and self. This interaction is exemplified by a discussion of the impact of meaningful connections on the development of social understanding, personality development, and the development of social and emotional competence in childhood.

Many parents believe that lecturing their children on the dos and don'ts is the most effective approach to impact their children's personalities. Children learn morals by mimicking their parents' behavior, not by listening to interminable lectures. As a result, the greatest method to instill confidence in them is to quietly promote good personality qualities in day-to-day acts.

I have heard of these online classes that are great for kids, they are called House of soft skills. You can check their website; they have a specialized course on Personality development for all the group ages of kids. Their courses have many different types of aspects. You can also book their free demo class, and see if it works for your kid. I think it is worth it. Personality Development