I agree it's bright but but it's not that bright..Actually I wouldn't know i think i need to get my parents monitior calibrated. Everythign looks really different on theirs from mine.

EIther way I think you should get rid of what looks like an applied image and gaussian blur set to a blending option liek soft light. I don't know if you did but if you did it isn't doing much for the BG (background).

The green and blue go well together but they are soo bright. The render isn't even that birght, it has no storng highlights and the white shirt looks more like gray, telling me he probabaly wasn't around a ton of light like this. IMO you should tone the light down.

Tbh I don't see a ton of blending either. It kind of looks like he was just slapped on top of the sig. I can clearly see each part of the edge of the render. Try to blend that in a bit, whether it bee with smdufging it, or clipping masks.

The backgorund is okay, it's just really chaotic. However the text..it needs work. IMO you should change your font, and the size of it. Try to stick to default fonts. It's a lot easier to make them blend with a sig than 99% of any font you are going to download.

Overall not too bad, just kinda bright and needs some blending XD.