Wow! ...Your top drawing is truly excellent! You are obviously a sensitive individual with a love of animals. The head & neck proportions look good. Because you haven't finished the "shading" on the L of the neck it appears to be thin. Is that the case?
My advice is to forget about using any HARD pencils. They can often tear into the paper. Next, don't always START your drawing from an outline & work inwards. Variation in line quality will always make a drawing more interesting. So, in other words, use thick, thin, heavy, light, sweeping, straight lines etc to give interest.
One observation about the nostrils - they are in the correct position IF you redraw the angle of perspective of the horse's jaw line so that its bottom R side is lower than you have drawn it. A suggestion for drawing eyes - drawing a dark even outline around any object or feature will flatten it so it loses its volume. This has happened here.
"SMUDGING" as a shading technique is not the best option to take to add volume & a 3 dimensional quality.
I will give WOM some useful websites for you that will clearly illustrate what techniques are possible.
DON'T be AFRAID of the paper or of making a mistake. Keep on making art because you have a natural talent!
Oh, I forgot to say that sometimes it is NOT what you put ON the paper that makes a drawing superb, but what you LEAVE OUT!
Regards, Karen