ok not bad, but there's a few things that could use some work. first, and most obvious when I first look at the sig, is the render placement. you have his head perfectly centered in the sig, which is something you almost never want to do. mostly you will want to have the head near the top to leave less empty space up there and to include more of the render in the image. next is the lateral placement of the render. I recommend reading up on the visual rule of thirds. your current sig has good render palcement, but this one feels almost stuffed in the corner.
not gonna go too in depth on everything on this one, but the other thing I wanted to touch on was the background. the background on this one is super overexposed, which draws attention away from the focal point. as a general rule, the background of a sig should be darker than the foreground (render) so you don't strain the eyes of whoever is looking at it. that's all I have for now but @boubabi is more knowledgeable than me on this stuff so if I said anything incorrect he can correct me