The sources and advice linked below are helpful. Given that we have no idea what level "from scratch" means, or your preferred learning style, I'm upvoting Khan academy on the basis of their map/pathway/dependency graph. Shows how topics build on each other and gives you a framework.
The other piece of general advice is to define what it means to learn math. You only learn math by solving problems with it. Do the exercises. The theory is only there to enable you to do the exercises/problem sets.
preferably on paper and pencil (yes even for sets of differential equations where you have to track 14 complex variables over multiple steps and you fuck up your answer because you mis-copied an exponent on line 12 of 35 lines. It is slow and difficult on paper, and that is an advantage when you are learning).
The other piece of general advice is to define what it means to learn math. You only learn math by solving problems with it. Do the exercises. The theory is only there to enable you to do the exercises/problem sets.
preferably on paper and pencil (yes even for sets of differential equations where you have to track 14 complex variables over multiple steps and you fuck up your answer because you mis-copied an exponent on line 12 of 35 lines. It is slow and difficult on paper, and that is an advantage when you are learning).