Eh well you're new to all of this so I'll give you some crit. We'll go step-by-step.

If you save your images in .jpg format always remember to save them in max quality.

I recommend you save in .png format next time. PNG images have better quality and are in fair sizes.

It's good that you're using tutorials. The sig you have here is pretty simple.
I recommend you check out some of the tutorials in the signature tutorial section of this forum.

And don't stay too long on sigs. After you feel a bit more comfortable with photoshop, move on to making bigger pieces in digital art. You'll progress a lot differently that way.