GReat start! CAnt' wait to see the finish.
As to the human drawing, i generally do not give advice when it isn't asked for, but there are two things that i believe would be beneficial for you to try. FIrst, put a mirror in front of you and draw your face by plane only. draw each seperate plane, there are a possible 6 or more to the upper lip alone. ACross all the features. THat will improve anyone's understanding of anything dog, cat horse, human...it is a hard excercise but imo totally necessary. THe second is to watch your lighting. Take something and pretend it is the sun. Place it where you want your lighting to come from, and remember to check your source of illumintation when you are shading. THat is an easy solution to a very important element of your believability.