Here is an example of a page. It is different from a blog post in that it will stay in the same place, and will be displayed in the navigation menu of your site (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:
Hello ! I'm a mechanic who aspires 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 that:
The company 123 Machin Truc was created in 1971, and has not stopped offering quality gizmos to the public since that year. Located in Saint-Remy-en-Bouzemont-Saint-Genest-et-Isson, 123 Machin Truc employs 2,000 people, and manufactures all sorts of cool stuff for the Bouzemont community.
Since you are a new user of WordPress, you should go to your dashboard to delete the current page, and create new pages with your own content. Have fun!