Feeding ChatGPT 3.5 a Single Document (about 8000 words) to Train for Accurate Answers to Questions Relevant to Said Document?

Can someone point me towards resources, starting points, etc. that would help someone achieve this goal of creating something akin to a chatbot that would give accurate answers based on a single document.

If there’s an existing tool out there that has this capabilities, that would be much preferred.

I forgot to add, we would be able to use chatgpt 3.5 16k.