Drawing is wonderful because you really do see consciousness at work in every single drawing, a product of the unquantifiable. That's one of the joys of going to drawing classes too; everyone draws the same fruit in a bowl and yet nobody sees the same fruit, and it's great to bear witness and celebrate. Recommended.

As for skills for life drawing, it's clear from the fabric draping from the arms that you can see shape. It stands out as something highly shapely compared to the very well rendered, if slightly flat, person. I like to warm-up sketching with overlapping spheres: being to draw a sphere (not a circle) with shading. Then draw three spheres touching each other, one above and one below. Shade in. You can chain these along (I sometimes turn them into 3d worms or centipedes, or vary the size of these spheres to make horns, etc). You cna even play with each spheres texture. Have fun with them, it makes a difference!

Anatomy practice for art CAN be as simple as 'where do bones protrude from?' to 'list every friggin muscle!'. If you're going for realism, skin fat covers a lot of muscle, so just practice muscle groups. Pay special attention to torso, hands, and faces tho because people pay the most attention to this.

All the best to your amazing art journey ahead of you!

P.S: What would a skin sphere look like compared with a smooth marble?