This is a sample page. It differs from posts because it always stays in the same place and (for most themes) is displayed in the navigation. Most people start with an imprint, privacy policy or an „About Us“ page with an idea for potential visitors to the website. For example, there could be:

Hello! During the day I work as a bike courier, at night I am an aspiring actor and this is my website. I live in Berlin, have a big dog named Jack, I like piña coladas, but I don’t like being left out in the rain (without an umbrella).

… or something like:

Our company XYZ was founded in 1971 and has since produced a lot of high quality ABCs for the public. Based in Gotham City, XYZ now has over 2,000 employees and is always making great things for the whole Gotham community.

As a new WordPress user, you should go to the dashboard to delete this page and instead create a new page with your own content. Have fun!