How should you start a career in Machine Learning?

Many people have gotten jobs in machine learning just by completing that MOOC. There're other similar online courses that help; for example the John Hopkins Data Science specialization. Participating in Kaggle or other online machine learning competitions has also helped people gain experience. Kaggle has a community with online discussions from which you can learn practical skills. Attending local meetups or academic conferences (if you can afford it) and talking to more experienced people will also help.