Machine Learning brings many new and exciting approaches, especially for mechanical engineering. The efficiency, flexibility and quality of the systems can be significantly improved with the help of the available data. ... Machine learning is an important part of computer science and artificial intelligence.
Well, here there are some prerequisites materials which you should learn first:
Programming skills (There are many videos on internet, Python) Linear Algebra (by Terence Tao) Probability and Statistics for Data Science (by Carlos Fernandez-Granda)
After that you can start these books:
Pattern Recognition and Machine Learning (by Chris Bishop) Deep Learning (by Goodfellow, Bengio and Courville)
For fundamentals visit statquest,deeplizard, and Siraj Raval on youtube. they describe all fundamentals simply as the must-read prerequisites and could give you some insights into the machine learning. Thereupon you could decide your direction based on your practical needs.