This is an instance page. It’s different from a blog post because it will remain in one place and will showcase up in your site navigation (in most themes). Most people begin with an About page that introduces them to potential website visitors. It might say something like this:
Hi there! I’m a bike messenger by day, aspiring actor by night, and this is my website. I live in Los Angeles, have a good mutt named Fap, and I like piña coladas. (And gettin’ caught in the rain.)
…or something like this:
The XYZ Doohickey Company was founded in 1971, and has been providing quality doohickeys to the public ever since. Located in Gotham City, XYZ employs over TWO,000 people and does all kinds of astounding things for the Gotham community.
As a fresh WordPress user, you should go to your dashboard to delete this page and create fresh pages for your content. Play!