Newbie - maintaining an existing corporate Drupal website

Hello all, this is my first time in a techie forum so forgive me if i sound dumb. I'm new to Drupal and i've been assigned the task of maintaining and updating the website of the organization I'm at. I'm having some trouble with some of its features and i'm hoping somebody can help me out.

I'm trying to add in a new block for a new page I created. Basically, there's a common block placeholder that appears on every page that has a link for feedbacks from visitors. There's a "general feedback" link for most pages, but for some pages, there is a specific link that takes you to a more specialized feedback page eg. "program feedback". So let's say that page I just created is called "Agencies". I created a block with the same html codes in the body section as the other existing specialized (custom) blocks, but for some reason, whereas the existing blocks show up with a green background, the block I created has a white background. I want the new block to mirror the existing "feedback" blocks, except with different text. How do I do that? I hope it's not too confusing to understand, I'm not sure how to explain this.

Second problem is with the rotating ad banner. We have a banner that displays random pictures that were originally uploaded by the web developer. Since I did not install and build this Drupal site myself, I have no clue where to find the folder to add more pictures for the rotating banner. Is there any way I can upload pictures to allow them to be displayed or must they be in the image folder on the computer? We no longer work with the web developer who developed the site so there's no way to know where the photos are stored.

Thanks for any help anyone can give me. I know my questions sound a little confusing!