Help me with an idea

So, i recently got whiff of localAI. I am looking to implement localAI (selfhost) to create a chatbot that gives details and explanation of contracts that i could upload to it. Anyone could you suggest me a modal to use or a simple overview on how should i proceed ? ( If possible i can train the modal with those docs ).
Another one is that just like GPT but i want it to be specific like i can give the modal the data and the GPT should answer in context with those documents ( essentially the above one but on a wider scale ).
Thank you. Appreciate if anyone could point me to related documents or repos.