How to write a self development book?

Hi everyone,
I hope you’re all well. I would like to write a book and I have some ideas about it, I know for a fact that the book that I’m gonna write is gonna be a self-development book targeted for young teenage audience aged 15+ and mostly female based, I assume for now, yet, it might change. The vague ideas that I have atm are around, healing after a long term relationship and how to create your dream versions of oneself, healing from traumas achieved by a toxic narcissistic dad in your 20s and basically feeling remarkably happy about yourself after healing and being in the stage of achieving your goals as a young girl who immigrated with her family to build a dreamful life. I now want anyone to advice me what to do next and how to start writing it. I am currently reading self development books myself because the ideas that I’ve mentioned come from my personal life and I want this book to be a mix of novel writing and advisable writing if that makes sense. any advice or recommendation would be great. I want this be to be published and obtain a lot of fans.