As an introvert with mild autism I always struggled to develop a personality but I can tell you what worked for me: Talk to people, even people you think you h

As an introvert with mild autism I always struggled to develop a personality but I can tell you what worked for me: Talk to people, even people you think you have absolutely nothing in common with (specially people from different cultural backgrounds than yours, if you have access to any) and ask them about themselves. Be curious and really try to be interested in what they have to say and try to get to know them as people without being judgemental (this was really hard for me at times because I tend to be too black/white). I started at work (because I don't socialize outside of work much) and I literally talked to anyone who would be open to in the office. I struggled at first because I wanted to be listened to too, I wanted to express my points of view, etc but I held back and asked people about themselves instead, after a while people will be curious to hear about you. Talk to enough people and soon everybody will know who you are, you will be known as a great listener and everyone will want to talk to you, confide in you. Try and learn from what other people have to say, their stories, their personalities, what drives them. This helped me immensely in developing a charisma, knowing what makes other people tic gave me a framework that enabled me to adjust my behavior accordingly. Anyway hope this helps.