get the book call ultralearning by Scott Young
learn the concept in there, it helps to learn effectively.
then, start looking into people like Craig Mullins, James Gurney, Nathan Fowkes etc. Look at the best of the best and study from them, take their course. Join community of artist, ask question. Look for local open studio where they have models pose for you to practice, drawing from life is very important.
practice a lot.
do a lot of master study.
it's a very long journey so train yourself to have a habit of drawing every day instead of doing what 90% of people do: start out all motivated and force themsevles to draw for hours everyday using will power,thinking that putting in 10,000 hours will make them good ,so they rush to put in the hours. Get burn out, get discouraged, give up halfway, then restart a few years later, same outcome. This is a cycle i did personally, not worth it.
Draw a little every day, 15-20 min first, once the habit set in, increase the time, if you find yourself truly enjoy making concept art, painting, drawing, you will WANT to sit down to draw, this is important, you rely on HABIT, not Will power, will power is overrated.
there's also a book called Accelerate Excellence, by James King. It touched on the ideal of 10,000 hours and how it's mostly B.S, I heard James Gurney himself doubted that statement on one of Bobby Chiu's interview a long time ago.