The best model for training

I need to train OpenAI model, so it will be capable to answer customers’ questions pertaining to particular sales business. This business has particular questions and corresponding answers that relate to its business topics that come up in conversations with potential customers and how they conduct their business.

  1. What would be the best model to train?
  2. What would be the essence of the training: fine-tunning API or embedding API?

I am also looking to Azure OpeAI API
How to customize a model with Azure OpenAI Service - Azure OpenAI | Microsoft Learn

But I don’t get whether they use fine-tuning or embedding - it simply called ‘training’ there