Changing your blog style is not just for layout, but also for what style of featured image you want. You get 4 blog styles, 8 with the pro version:
Setup Longevity
Welcome to the setup tutorials for the free WordPress theme named Longevity. Please note that any support you may need while setting up this theme is available to you by going to the theme’s download page at wordpress.org and click on the “View Support Forum” button.
Change the Site Title or upload a Logo
Longevity starts you off with the Site Title and Tagline, but you have a Several options: