Edit the text of my header

disclaimer: I have zero coding or web development experience and I’m just throwing myself into this …

Anyhow, I just paid for a theme (I think its called “Creative Blog Responsive WordPress Theme”) and its on the website but the name of the theme is still the title of the website.

I’ve gone to settings => general => edit site title … but it doesn’t change the text of the header.

Please! Anyone!