Here is an example page. It is different from a blog post, in that she will stay in the same place, and will appear in the navigation menu on your site (depending on your theme). Most people start by writing a "about" page that presents them to potential visitors to the site. You could write something about it:

Hello! I am a mechanic who aspires to become an actor, and this is my blog. I live in Bordeaux, I have a super dog called Russell, and I love vodka-pineapple (as well as wasting my time watching the rain fall).

… or something like that:

The company 123 Machin Trick was created in 1971, and has not stopped offering the public quality widgets since this year. Located in Saint-Remy-en-Bouzemont-Saint-Genest-et-Isson, 123 Machin trick employs 2 000 people, and manufactures all kinds of super widgets for the bouzemontoise community.

Given that you are a new user or a new users of WordPress, you should go to your dashboard to clear this page, and create new pages with your own content. Have a good time!