I forgot to mention this in my first response, but actually model the anatomy you are studying as you go. You don't need to make highly detailed or precise models, but building a 3D human piece by piece will go a long way for your comprehension of the whole structure, and also it will be practice modelling organic forms. I suggest starting with the axial skeleton, then move on to the appendicular skeleton, then the skull (which is waaaaaay complicated), then the muscle groups from inner-most to outer-most. If you really want to top-out, you can study sub-cutaneous blood vessels, but that's not essential.
Also bare in mind that males and females are skeletally distinct, especially in the skull and pelvic gurdle. After studying anatomy, you'll want to learn about the sexed distinctions. In addition to sex, human from different regions of the world have skeletal distinctions. For example, African people commonly have jaws, chins, and nasal bones that protrude almost a whole centimeter more forward than the rest of the world, and many Chinese people have nasal bones that turn inward instead of outward, compared to the rest of the world. Research into details of this kind will become essential in the future, when you want to design an original human character. You'll want to know what are the skeletal distinctions that might by found in that character by sex and region, so you can make a mock-up to model your mesh around.
You're absolutely right that it is a long journey, but, consider these things:
It's no different from studying a coffee cup, except a human is far more complex than a cup. For anything you want to model, you will need to study it, no matter how simple or complex it may be.
Whenever you see 3D humans that look not-quite right and compare them to some that look just fine, the difference is often that one of those artists has not put the proper time into studying human anatomy, and the other artist did. That knowledge is the difference between them.
I wish you luck!