What exactly do you feel you need help on? People might be able to offer more specific advice if your question was more specific to your problem areas.
You seem to have a chibi anime style going on in your work, and it is a concurrent theme. This can work, but only if you take advantage of the pros and cons of drawing in chibi; namely learning how and when to super deform a particular feature, when to add some realism, proportions for chibis, etc. Some people have this idea that drawing chibis = easier way of drawing anime, and depending on how detailed you plan to be with it, its actually not the case at all, since you basically have to take the human anatomy and then simplify it even further. Simplifying something doesn't necessarily mean its easier to, as it can take some getting used to, and a commitment to a style that does have its limits.
Are you content to draw in a chibi style? I'd start by asking yourself what it is about chibi size characters that make you want to draw them, and then focus on those things and analyze them on the technical level. You might just be inspired that way.
As for this actual sketch, its not that bad actually, as you clearly have a theme that is well executed, and this and your other pictures have charm and character, a definite plus if you're going to commit to this style for any length of time.
i actually am learning my own chibi art thing is that, the coloring i'm not so good with mixing multiple hue together so i go for black and white i also got inspired by Sin City (comic/movie) and Dogs: Bullet and Carnage (manga/anime). If you look at the art you can see it's heavily inked and sometimes go for the extreme (like Sin City style where you can hardly see any line sketch or indication, more of a painting without a single frame). I found inking is insanely hard so i love to give it a try, and end up with this series of mine i'm having a difficult time finding someone who's good, advance, or even master the technique of inking to help me out. Sometimes details on my picture don't come out as expected. Lineart is a fine thing to start with, but how will i color it as will? some people find it easier to mix and mess with different colors, while i'm trying to focus on only 2 colors well, thanks for sharing your advice and care i'd hope to see your new deviations
Theres lots of different ways to learn and explore using black and white, and it has mostly to do with technique. Have you experimented with spotting, cross-hatching and techniques like this, or are you just filling in areas with black? Depending on what you want visually, you may need to learn some additional techniques if you plan to work primarily in black and white.
Its to be expected that, if you've worked in black and white mostly, color will be hard for you, since there are many more things to consider, and color can completely change the look of a picture.
For now, I would start slow and don't try and do too much, or more than you know you're ready for. Set realistic goals that are practical and can actually be accomplished.
actually it's by pen i'm thinking of posting a picture of my pen later XD and another thing, "1st try" means 1st time on deviantart, if you look through my gallery you can see the original 1st time picture similar to this, though, worse than this one X)