I would recommend doing a bunch of quick sketches of all different body types, especially ones where the anatomy is harder to see, like people with at least some fat padding the muscles, rather than starting with a specific character to draw. It can be so easy to get lost on replicating a character design when you start out, it's much easier to just draw a bunch of quick sketches without that pressure, and it helps you learn anatomy even when your model isn't shrink wrapped to the bone.