I want to know how i can train my own llm to have a certain knowledge about a skill or niche eg: if i want a chatbot that talks to people to recovering addicts about their addiction. i want to train it so it knows how to talk to such a person in a way that is suited best for people that want to stop their addiction. after that i want to use that llm and create personalised chatbots using prompts for each individual.

so an LLM-> trained to my liking and needs -> set up chat bots for each individual person and with each their own prompts and character.

what are the best tools to make this.