Here is a sample page. It is different from a blog article, in that it will remain in the same place, and will be displayed in your site navigation menu (depending on your theme). Most people start by writing an "About" page that presents them to potential visitors to the site. You could write something of this tenant:
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 named Russell, and I love the vodka-pineapple (as well as watch the rain fall).
.. .or something like that:
The 123 Machin trick company was founded in 1971, and has continued to propose to the public of widgets-quality stuff since then. Located at Saint-Remy-en-Bouzemont-Saint-Genest-et-Isson, 123 Machin trick employs 2,000 people, and manufactures all kinds of super doodads for the bouzemontoise community.
Since you are a new user of WordPress, you should get on your dashboard to delete this page and create new pages with your own content. Fun!