this probobly has a very simple answer but here it goes...

in the center of the main page i see news,ect... in what look like a block
has all the borders like a block
how do you get those there like that, i think it would look much better to have them like that instead of a simple box.
can someone explain how to do that please

you need to be more clear.
can't understand what you want.

you know how the blocks have thier own borders using graphics or whatever.
well the center news,ect... usually has a plain border.
i have seen news using the borders and graphics the blocks have and would like to know how to make that happen

That is part of the theme, Depending on the theme - some have 3d borders in the center.
or mod your own theme.