Here is an example page. It's different from a blog post, in that it will stay in the same place, and show up in your site's navigation menu (depending on your theme). Most people start by writing an “About” page that introduces them to potential site visitors. You could write something like this:
Good morning ! I'm a mechanic aspiring to be an actor, and this is my blog. I live in Bordeaux, I have a great dog named Russell, and I love vodka-pineapple (as well as wasting my time watching the rain fall).
…or something like this:
The company 123 Machin Truc was created in 1971, and has continued to offer quality gadgets to the public since this year. Located in Saint-Remy-en-Bouzemont-Saint-Genest-et-Isson, 123 Machin Truc employs 2,000 people, and manufactures all kinds of great gadgets for the Bouzemont community.
Since you are a new user of WordPress, you should go to your dashboard to delete this page, and create new pages with your own content. Have fun !