Someone wanted to learn this too, so Grasp built them a personal learning path.
You can keep exploring this one or create a path like this one shaped around you.
Recommended resources
Module 2
Matrices and Linear Transformations
Module 3
Matrix Decompositions for Machine Learning
Module 4
Fundamentals of Calculus
Module 5
Multivariable and Matrix Calculus
Module 6
Probability Theory Foundations
Module 7
Multivariate Distributions and Statistics
Module 8
Information Theory for Deep Learning
Module 9