To become a good machine learning engineer, it extremely relies on the state you are in now. Like, if you are a computer science graduate then you must have a sharp edge over Machine learning then I advise you to pursue a PG course on data science which deals with Machine learning till advance level. Because at the graduate level in CS you will not have that much part related to ML that deep. Attempt to understand the fundamental concepts of Machine Learning. If you want to out-master this technology then you need to go deep down to the sources, before penetrating stem & branches. There are a lot of open-source and online MOOC courses assisting people to find a basic understanding of the same. Now, MOOCs are not a strong way to believe that, you'll learn ML, but they are good for beginners. If you are a beginner and want to know more about Machine Learning, then check out this course by Intellipaat which will teach you ML from basics: Machine Learning Course
And if you are more into youtube tutorials then here is an awesome video tutorial by Intellipaat which will clear all your doubts regarding the same: