Wordpress theme building question

[Mike Teezie]

I'm working on a new theme for a website right now. WHat I am trying to do, is have a static "welcome" div I've written up show up only on the home page I have designated. I have the home page set to a static page in Wordpress, and that's the page I want the welcome div to show.

Would I do this with the function.php file? Or would I made a whole new php file called welcome.php, and somehow call that only on the home page?

First, let me say I'm a total idiot with php. My knowledge goes so far as css, and that's pretty much it.

I've attempted to google for the answer, but I'm afraid I'm wording my searches in a way that won't find me the answer.

As always, thanks in advance.