Modify “chromatic-rounders orange” theme

Hi, I am trying to modify the “Chromatic-Rounders Orange” theme to accommodate a 3rd column. I would like to take the existing column and switch it to the left side and add a right side column to host ads. I have modified the images and was able to accomplish the “switch” of the existing column to the left side, but have been unable to add the 3rd column. I would also like to add a custom header above the current header, while keeping the current header for messages. I am fairly proficient with html as well as css and have added a 3rd column to a “blogger” template, but am new to WordPress themes and PHP. Any help that could be offered would be much appreciated, thank you for your time.