- MIT 18.06 - https://ocw.mit.edu/courses/mathematics/18-06-linear-algebra... - The lectures and the textbook for the course are a default recommendation.

- Linear Algebra Done Right - This is a textbook, there are also youtube videos from the author - https://www.youtube.com/playlist?list=PLGAnmvB9m7zOBVCZBUUmS...

- Khan Academy - https://www.khanacademy.org/math/linear-algebra - Also a good place to start, very accessible, missing some of the more advanced material.

- 3blue1brown - https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2x... - These videos are good but they're more of a nice overview than a way to learn.