here Let me send you the links(you don't have to go in them.... It's fine..)(and also, don't freak out cuz it says precalc, It's just the label... I learned this before algebra1 so the labels are kinda off sometimes...):
Matrices: https://www.khanacademy.org/math/precalculus/precalc-matrices
Vectors: https://www.khanacademy.org/math/precalculus/vectors-precalc