Is there a site like fast.ai or deeplearning.ai but for machine learning instead of deep learning?
Can't comment due to low reputation, but as a comprehensive summary I'd recommend Elements of Statistical Learning by Hastie et. al. It reviews most current state-of-the-art ML methods, together with the classics, is free of charge (big thanks to the authors!), and even has a nice accompanying R package.

It's probably not the source you've expected, but is really a nice place to start, especially for practitioners.