Let me start off by saying "I Like!"
Now, because I like it so much you get a critical review!
All of this is meant to be constructive. For a "new guy" you seem ready for your next step.
1. Which black costume? If it't the venom costume then you're fine. I've always pictured it as a super form fitting, no seams, glossy oil costume. If you're going for spandex then you need seams, and texture. The seams can be done with a mask and the dodge and burn tools. The texture is little more than a subtle noise filter. (You hit it with your other spiderman pic.)
2. The Emblem. The emblem needs more perspective and "wrap" around the body. What program did you use? Chances are that somone here can show you in whatever program you're using.
3. Background lighting. You've got a nice, dramatic pose and background. I would propose more, subtle backlighting or highlights in the costume to kick him more from the background. Probably no more than 25% of white or yellow.