AI is just general term while machine learning, deep learning, and whatever learning are overall method/algorithm to implement AI. You can start from any of them, but at the end you need to consider of your goal, amount of data, time for training, and purpose of AI. You should pick one that fit your need the best.
But if you just want to learn about it. There are several on-line courses, but I recommended https://course.fast.ai/ since it walks you through basic and give you idea (how-to), including example to use the libs.
It may require you to know about computer programming language like: python, java, etc; and mathematics like matrices, vector, tensor, among other things.