just…go at it, I guess. that’s not the advice anyone wants to hear, but the only way to get good at something is to do it, all the time, for a long period of time. start with whatever resources you have available to you, don’t pull yourself back by thinking any particular material or program will make you better faster.
it’s sort of a vague question so I don’t know how to give a more specific answer than that, but know you don’t have to be and won’t be good at it right from the start. the only way to get better is draw and draw and draw and draw, and keep drawing when you do get better, and keep drawing after that because you’ll continue to learn and improve.