Customize - Site Title & Tagline
The name of your blog (Title) will be your trading name, so treat it well! Your tagline is a short summary of what your blog is about!
Your title and tagline appear at the top of web browsers, and in tabs within web browsers. To change this simple open the customizer. Just hover over your blog’s name in the admin bar and click Customize. Once it loads, look for the Site Title & Tagline
As said, these names are important. Properly enter them and save!