How do you do the background of that? I've seen that kind of style and I was wondering if there was any tuts that can teach me it?

Thanks for your time and please help

Gradient.
Then make a new document.
i think it was 5x5 pixels
Cover it with a diagnal pixel so it looks like this


xoooo
oxooo
ooxoo
oooxo
oooox

x representing the line and o representing blank spaces. or the other way around (just make a 5by5 diagnal)
then save that as a pattern.
go back to your gradient and do pattern overlay with the pattern you just made(aka scanlines)

I think this is how you do it o_O

Thank you.

Outcome: