Download some fonts(text) here,it needs to be more alive:
www.dafont.com
www.1001freefonts.com
www.fonts.com
Also,don't try to lower the render size too much because it is too small for the whole signature and might destroy some pixels.
Also,you need Focal Point,Depth,and to blend everything perfectly,seems like you deleted some pixels from the images you added your signature and it doesn't really seem to help because of it being unnoticeable. This is actually better than some new signatures created by some people so you did a great job on your first signature!
For beginners,smudging is highly recommended.
Here are some tutorials that might help you with that:
Tutorial - Basic Smudging
Also,here are some tutorials for C4Ds:
3 Tutorials - C4Ds
Here are some video tutorials for C4Ds:
https://www.youtube.com/watch?v=qDUDZCNN2Tc
Hope to see improvements soon!