This is an instance page. It’s different from a blog post because it will stay in one place and will appear in your website navigation (in most themes). Most people start with an About page that presents them to potential site visitors. It might say something like this:
Hi there! I’m a bike messenger by day, aspiring actor by night, and this is my site. I live in Los Angeles, have a supreme mutt named Jack, 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 giving quality doohickeys to the public ever since. Located in Gotham City, XYZ employs over 2,000 people and does everyone kinds of epic things for the Gotham community.
As a new WordPress user, you should go to your dashboard to delete this page and create fresh pages for your content. Have fun!