You requested some tips, so here I am.
Colored pencils are one of my favorite media, so first of all, never feel like you need to use expensive pencils like prismacolor. You don't need expensive anything to draw good or enjoy drawing.
The only speciality tools I recommend are a kneaded rubber eraser (a white eraser is the next best thing, most mechanical pencils come with one) and sketching paper. A lot of people starting out don't like the texture (tooth) that sketching paper can have, there are plenty that are smoother, just feel before you choose. Can you draw good on printer paper? Yes, it just shows erase marks clearly and the paper gets an impression from the pressure of the pencil which stays. Can see that in the legs you redrew of the kabuto. Also printer paper can have logos/recycle symbols on them which are more visible if you hold it up to the light.
There's already some improvement in what you've posted, so that's nice to see. I think you should start experimenting with color. Colored pencils are all about building up color. If you color too darkly the paper is going to be maxed out on how much more you can put on it. Start coloring lightly and then go over it until you get the darkness you want. Second big thing, try not to use colors straight off the pencil. If you don't have a giant selection of colors to choose from it can get boring. Don't use the green you're given. Make it with yellow and blue. Don't use the brown you're given, try combining red and green or red and yellow and blue. You'll get different color browns this way. Primary colors, white, and black rarely exist in nature.
There's different ways to color with colored pencils, you use different strokes for different effects. Usually I use a circular stroke, this prevents the color from being uneven and streaky. I'd find a tutorial, video or image, that uses this technique because I know that description is lacking. About the only time I don't use this technique is if I'm coloring long hair, and even then I start with a solid color base. You might see things mentioning the use of a blender for colored pencils, honestly don't worry about it, it's not important at your level and it's really a personal preference kind of thing.