Drawing online? I don't know how you'd plan on doing that.
What I recommend is stick to paper and pencil for a while. Before attempting anything, you should get a good feel for anatomy: proportions or body ratio mainly.
Seeing as you're new to drawing, it would be a good idea to get a book. Books on Anime drawing usually have either one or two sections dedicated to anatomy. I'd recommend you starting with that, and then deciding with if you want to stick to anime or cartooning.
For your current drawing, here are a few places to start.
Body Ratios: Try to look at yourself in a mirror, and think about how your body parts compare to each other. How wide are your shoulders compared to your head? How thick are your arms compared to your torso, how thick are your legs compared to your arms. As a general rule, there's no way legs could be thinner them arms, unless you're a species that hangs from monkey bars from the roof all the time >.>
Relationship between limbs and body: Arms and legs stick out of the body at the shoulder joints and hip joints. Remember that there is a skeleton beneath each person, and that in drawing, you must keep that in mind. The way your legs stick out right now makes it look like they meet at one central point. Legs don't.
Hands: Okay, usually, I like to mention concepts like those mentioned above rather than single points, but try to pay more attention to your own body when you draw. Fingers are not bumps out of a lump of flesh. If you've ever looked at the skeleton of a hand, the tarsals, the metatarsals, the phalanges, you'll notice the hand is actually much more streamlined, and that the thumb is not a regular finger. It sticks out the side, and contains less joints. Try taking a piece of paper and draw just one hand, paying attention to the way its built.
Its awesome and you want to draw. We all must start somewhere. Try paying more attention to reality while drawing. It helps. Keep on practicing.