Best AI for my use case?

I have a bunch of notes I've made on a topic that I now want to create my own gpt for, for eg, 'maths gpt' or 'data analyst gpt' where I put all my notes into the ai so it can then be used as a personal tutor.

What would be the best AI for this? I've read about some models not being to get that deep into my notes etc. It's a case where I need the model to always be accessing my notes because I want to be testing thoroughly and can't afford for any of the notes to be left out.