Dr. Bharatendra Rai
On his YouTube channel, Dr. Rai uses R for an impressively wide variety of machine-learning tasks. I especially found his videos introducing Keras to be informative and developed an interest in the topic myself. If you are a more experienced R user, looking to use R for machine learning you may want to check out his YouTube channel. Here is a small sample of the machine learning topics he has covered: linear regression, logistic regression, ensemble methods, classification trees, multinomial logistic regression, and deep learning.