You need to pick up problems and do them. Pick up a problem and learn the math for it, then code it, and then if you like, publish it or blog about it. You only learn a subject by doing problems. So, you need to think about the list of problems you're going to solve. Here's a starter list - make a recommendation engine for books to read for a user, make a sentiment analysis prediction algorithm for hospitals based on patient feedback (textual), make a spam detection engine for sms'es you get on your phone, make a multi document summarizer, make a prediction model for predicting whether a certain flight would be on time or not, make a bot application for your phone such that for everything you want to do on your phone you just go to that bot application and type in and tell it what to do, advance your bot by taking voice instructions, make a AI game to play tic-tac-toe - make your friends play with it and let it learn / grow it's training data and then it should improve in beating other people. If you only do these, it'll take you a few months. But like they say - "when you want to learn something, assume you have all the time in the world". Best of luck!