If you are interested in getting started with Machine Learning, the TensorFlow Playgroundcache is a good way of building some intuition.
For a first introduction to the field, I recommend Neural Networks and Deep Learningcache, followed by the Deep Learningcache book.
To dive into a specific topic quickly, the TensorFlow tutorialscache are also great, Dive into Deep Learning has a lot of detail as well.
For Reinforcement Learning specifically, the standard text is Reinforcement Learning: An Introductioncache. Dave's UCL Course on RLcache is great too (playlist of all lectures).