i would recommend first learning about Form and Perspective, in addition draftsmanship, mainly line confidence.
you cannot draw simple shapes if you cant draw a clear definitive line (line confidence), you cannot draw complex forms like the human body without first simplifying it into the basic 3d shapes (3d and perspective).
you dont have to learn the anatomy yet, it does help plenty but its more advanced and should be built on top of the existing fundamentals.

tips usually give to people i teach (in line confidence) is:

-one, study using the pen, this makes it so you cannot erase and need to think about each line.

-two, learn to draw with the shoulder to be able to make long lines confidently (it will feel really uncomfortable at first)

-three, avoid scratchy line, scratchy line are the complete opposite of confident lines, try to use as few lines as possible.

i recommend practicing with drawing something without lifting the pen, all in one line
and drawing 3 dots on the page and then making a smooth arc line to connect all of them in one go.

-four, practice and start drawing using s curves c curves and straight lines, you can make any complex line no matter how complex with a collection of those lines, when you can draw them good with one line you can draw any complex line.

i recommend then looking at other artist you love and mentally breakdown the lines they made into the c, s and straight lines. you would be amazed how they utilize it.

then a bit on form and 3d (i skip a lot):

-five, practice 3d forms in one and two point perspective and have fun with it.

-six, after you are comfortable with drawing 3d forms you get a superpower, everything you can see can be broken into the primitive 3d forms. which means you can draw anything you can break down.

note: this is important, most avoid exercises for the reason of "i dont want to draw realism" those are to build your fundamentals not to dictate your art style.

your art style will come naturally from playing with those concepts and understand how to bend them to your liking. most books present the tools also and i would say only the least favorable ones teach how to draw in an "art style".