I highly recommend Interactive Linear Algebra for learning undergrad-level linear algebra mostly in the R^N. It has a PDF version available, but the real magic

I highly recommend Interactive Linear Algebra for learning undergrad-level linear algebra mostly in the R^N. It has a PDF version available, but the real magic is in the interactive embedded 2D and 3D visualizations. There's a couple of variations available - it was written by some professors at Georgia Tech, one of which moved to Duke and teaches off of it there - but the UBC version is my favorite, as it makes some changes in the lesson order to teach vectors before matrices. https://www.math.ubc.ca/~tbjw/ila https://www.math.ubc.ca/~tbjw/ila