Latest post formatting

I’m designing a new theme for my wordpress site and am wanting to make the first post ‘highlighted’ I’ve designed a rounded box for this so I need to have three div’s for it to show how I want. I’ve found the code so I can format one div differently, but I’m not sure how to expand on this to show the other two div’s. I also want to format the text differently as the colour for the text.

Unfortunately I know little php at the moment and I can’t find anything that’s much help to me on the net. Can anyone suggest something?

Thanks in advance