Khan Academy
Sal Khan's patient video walkthroughs of vectors, span, null and column spaces, linear transformations, inverses, determinants, orthogonality, and eigenvectors. The place to start if you need linear algebra from scratch before any ML math course.
Beginners building toward ML. This is a beginner-level course in Data Science & Math for AI, running about Self-paced (3 units: vectors and spaces, matrix transformations, alternate coordinate systems).
Free. No payment required at any point.
Rafael Irizarry's nine-course sequence teaches R, probability, inference, regression, machine learning, and productivity tools, ending in a capstone. For learners who prefer a statistics-first, university-branded path into data science.
Google's entry-level analytics program covers the data lifecycle, spreadsheets, SQL, R, Tableau, and a case-study capstone. The best-known on-ramp for people with no technical background who want data skills before tackling ML.
Twelve courses from Python and SQL basics through data visualization, machine learning, and a capstone, with no prerequisites. Suited to career changers who want an employer-recognized, end-to-end data science credential.