Watch this videoseries to get an understandig of what machine learning is and how to run stuff locally
https://www.youtube.com/watch?v=Coj72EzmX20&list=PL7RwtdVQXQ8rC_HTxaHuw15teD_44Yia6
This video is a good starting point to understand what a LLM is, how it works and software to do both training and inferencing (getting to production)
https://www.youtube.com/watch?v=2orLCp984HA