Start by learning Mathematics like Statistics, Regression, Algebra, Calculus.
Learn the mathematics behind data science from Andrew NGs Coursera free course.
Learn machine learning algorithms and how to implement them in Python from Kirill Ermenko's Machine Learning course on Udemy. Kirill Eremenko
Practice more problems, learn from other's code.
Register on Kaggle and practice there.
Read research papers
Follow people who are into Machine Learning to stay up-to-date.
Get an A.i internship, don't focus on the stipend, get one where you can work closely with the artificial intelligence team.