This is a sample page. It differs from posts in that it stays in the same place and (in most themes) is shown in the site navigation. Most people start with an imprint, the privacy policy, or an “About Us” page to introduce themselves to potential visitors to the website. It might say something like this, for example:

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

…or something like this:

Company XYZ was founded in 1971 and has been providing the public with high-quality products ever since. At its location in a small major city, the company employs more than 2,000 people and supports local residents in many ways.

As a new WordPress user, you should go to your dashboard to delete this page and create new pages and posts for your website. Have fun!