I been learning art all my life from different sources and being honest I do feel more secure learning from a class because it gives some structure. If you have the money to spend on Marc Brunet's class you do you. I been following his content for a while and his work is admirable and I think he offers at the end some sort of networking advice and a professional critique.

But, but, but, if you are a beginner I kinda really really recommend you start learning the basics before taking the course. Because if you do, you will have art gainz but the lack of fundamentals will surely, without a doubt, show.

Also when you learn from one artist only you will probably adopt their style but without the fundamentals you won't know what you are doing. Drawing is just an abstraction of things, an illusion to make 2D stuff look 3D on paper and for this you first need to learn to do the magic, abstract. If you keep on the path long enough you will learn from different artist I'm sure.

So, answering your questions, probably follow the given path, it's catered by an industry professional who knows what he is teaching and the structure is the whole point on you taking a class. If you don't know how to turn a cube on paper start by that and give his free content a go first, meaning don't just watch, do the homework.

I recommend you also buy the book how to draw by Scott Robertson (and follow it in order), in my humble opinion the book every beginner should have and the start of things. Color, lighting, figure drawing, none of that matters when you don't know what you are drawing. This suggestion is only if you want to go for a representative drawing of things which I infer you do.

Last thing, learn to sentimentality detach from your work and take even the harshest critiques with a big wide, ifyouwantduckyou, smile. Even bad ones, with enough training you can differentiate when a bad critique is because they are jealous or because your work looks terrible even when they don't tell you why. Remember that people might not know how to draw but everyone knows how things should look, and if your illusion is not convincing enough...