Here are my suggestions
- Focus on the detail in the armor not the legs, the legs might as well jut be shapes
- Google the human dimensions chart on images because it gives examples of how long something should be based on another thing, like how your height is equal to the length of your middle finger tip to your other middle finger tip
- Watch some tutorials on feet and hands, because they are really hard to do without teaching and practice
- Art styles, look for some art styles that would work good for you in this type of art