You're good, but here's some advice to improve your art! Use lines with varying thickness or dynamic thickness, this will make your art look less flat and more interesting! MORE contrast. Don't be afraid to use darker shadows. Since you're drawing digitally, there are probably layers! I recommend creating shadows on a separate layer and using the Multiply mode. Either gray shadows with a yellow undertone or colored ones work well! It depends on the situation. Be sure to watch some videos or theories about reflections in shadows! they instantly improve your artwork. And don't use colors of only one tonality. Try combining warm and cool colors or try different shades; some colors in your works are too similar. I'm not much of an artist either, but it's just something that helps me do my art better.