To change the logo: https://www.zen-cart.com/tutorials/i...hp?article=125

To change "sales message goes here": https://www.zen-cart.com/tutorials/i...hp?article=127

What template are you using? BOX_INFORMATION_ABOUT_US doesn't appear to be a standard Zen Cart constant. You can search for it by using admin>tools>developers tool kit. Type the constant you are looking for in the box at the bottom of the page and select "all files catalog/admin" before clicking the search button.