Creating Child Theme

I’m very new to WordPress.

I followed the instructions for creating a child theme based on TwentyTwelve. I created a folder in my themes folder calling it ‘gp’.

I then created a style.css sheet and put in what the guide said on WP. And I went to my admin section and activated the child theme.

But I thought it would then look the same as the TwentyTwelve theme, but it’s not, it’s go no style?