Still life is an excellent starting point
I also see that you chose the default isometric view, a nice starting point for perspective
As you start to get more comfortable, it's better to use less strokes in order to make the line-art cleaner, like you did more on the second
The shading on the first could be smoother on the bottom of the plate and it's really good that you remembered to use reflected light on the shrimp
Concerning the shadows, be sure you stick to one light-source, because the sushi is getting it from the front top left while the dish is getting it from the top left
Final notes: to make the dish seem shallower, use softer strokes to emphasize a curved slope. Most importantly, when shading, try doing so in the direction of the contour. (That is, shading along the outline instead of just going left to right/up and down
Keep it up and you'll be part camera ;)
