That my dear, were the key words why the left part ended up that way xD
I can go again and write a big wallie what you can fix and whatnot, but I think it's not needed here. You saw the mistakes yourself. Not to mention that this is your first signature so it doesn't looks that bad and you will still have a lot time to fix it. All I can see is that you were trying to go for that goldish colour which is nice, but I see some green spots here and there, I'm just not feeling the green that much, stick up with the goldish/yellowish. What you can do to fix this is just make a new layer; brush the green parts with gold/yellow colour and put the layer on either hue or colour on like 80-90% opacity; it shall work I guess. Yeah, the render is not that bad, you just need to blend it better with the background and use better c4ds next time. Keep up the good work though, it looks good for a first signature! All I can say is that practice does not make perfect. Only perfect practice makes perfect.