There are a lot of free wordpress themes available on the net, just google it.
Yes, there are -- about three of them for every active WordPress install, as far as I can tell, and a few hundred of them are available for preview right here (in the
Graphics & Webdesign forum). The problem isn't finding
a WP theme, it's finding
the right WP theme, and it is fair to ask for recommendations. Paging through tens of thousands of Google search results is only fun for so long, you know.
That said, "I prefer a white background" is a pretty broad requirement. It doesn't help anyone make a recommendation, really, since it doesn't describe the purpose or "feel" of the desired site. Here, I'm talking about things like whether the site is intended to be serious and "newsy", or light and fun, or whether it's primarily concerned with making long text articles readable, whether graphics make up a big part of the site, and so forth. Is typography a concern, and if so, do you need non-Latin language and character set support?
There are a lot of things that go into choosing a website's design. One of my favourite sites is
Smashing Magazine, an online magazine for web design professionals. They regularly run a list of well-done, professional-quality
freebies, including WP themes, that are worth a look -- they're usually rather striking and have an obvious genre fit, so you don't get the feeling that the content has been shoehorned into a one-size-fits-all generic template.