You need mainly probability, statistics, multivariable calculus and linear algebra. It's a lot of material to cover and it takes years. I would suggest to pick

You need mainly probability, statistics, multivariable calculus and linear algebra. It's a lot of material to cover and it takes years. I would suggest to pick a mathematics course/book that's just above your current level (whatever that is) and start there. That shouldn't stop you from doing kaggle competitions right now though if thats' what you like. Personally I dislike kaggle but there's no reason why you can't just grab a dataset, experiment with different algorithms and learn as you go.