Please comment, it's my first one

Yes it is good, I'm sorry for saying it is a google picture bro.

Thanks man

Its cool. But. Its good for your first though i doubt you made it.

1. Its a google image?
2. Why does it say urmybch1 at it, if you made it?
3. What's the reads stuff in the top right corner?
4. Why so blurry background?

Ninja, Because he is my brother and made it for my birthday.
Only the spiderman was a google part
Also, You might want to try and take out some of those effects and such.

It wasn't from google though, it was from a site that had tons of renders, and I wanted to make it look kinda like water

Actually it's not a banner...
it's a signature ...
The text is too small i can't see what's writen up there i see some blurry elements on the left side of his head (i mean our left)
arround the neck there.
Everything else looks like just smudged up i don't like it ...
If you're working in Photoshop i can recommend this site
http://digitaldelusions.com/site/?page_id=416
it contains a few good tutorials about making some GFX ...

Looks like a palette to me.

Back on topic, I kinda like it.
Although the text could be a bit bigger.
And it doesn't seem like you spent a lot of time on it, unless you made the background yourself.

I'd give it a 6.5/10, for now.

It's not really a banner, looks like a sig so I'll critique it as such.

That stock has a lot of potential for flow and depth but you didn't achieve either.
The background sucks :/. Need a stronger liquify effect to be more effective. It should probably go with the flow too, but it's doesn't.
The render needs to be more blended with the background. Try erasing the outer edge of render to achieve it.
Use some light blur in places on the render away from the focal to create depth. Sharpening the render helps too.
Needs lighting. Create a light source in a place that makes sense depending on the render.

I dont think thats spiderman... deadpool i believe

looks good, though im not sure what is your work and what was the render