I second referencing. It is an incredibely useful tool that you should absolutely take advantge of when learning.
I would also recommend viewing the skeleton of what you are trying to draw and learning how to simplify it down into shapes/lines for drawing. This will teach you to build a skeleton, then add the mass to it.
Start off with shapes! This helps me a lot. Use circles, squares, triangles, etc when building up the mass of what you are drawing. Learn the shapes of what you are drawing.
How I learned was to first trace over a photo of what I'm learning to draw, and note their basic shapes and simplified skeleton. Then, directly reference that and sketch it a few times. After that, practice drawing without directly looking at the reference; try to come up with your own poses or copy new poses. Don't post any of these unless you have permission to do so (except the tracing; I would not post traces), and always give credit to your references when you do post them.
These are just things I've learned while drawing. I'm by no means a professional, but I do hope these help you.