This is a sample page. It's different from a blog post because it will stay in one place and will show up in your site's navigation (in most themes). Many people start with an About page that introduces them to potential site visitors. It might look something like this:
Hi! I'm a bike courier by day, aspiring actor by night, and this is my website. I live in Los Angeles, have a big dog named Jack, and I like piña coladas. (And getting caught in the rain)
... or something similar:
XYZ Gadgets was founded in 1971 and has been providing the public with top-quality gadgets ever since. Located in Fantasyland, XYZ employs over 2,000 people and makes all sorts of fantastic gadgets for the Fantasyland community.
As a new WordPress user, you should go to your Noticeboard to delete this page, and create new ones for your content. Have fun!