Generally speaking, I organize my folders by type of program (IE Webinar, Tradeshow, etc), and then have subfolders that correspond to each quarter. This helps with my reporting in particular, because when my boss/manager wants to run reports, they can simply select that quarter's folder. It also makes it easy for when you want to run something cumulatively by channel type.
For your new program, be sure to select the program type as "advertisement". Adjust the progression steps as needed in the admin section. Then be sure to host all assets within the program. Keeping all of your assets within the program will help save you loads of time. Simultaneously, be sure to save more "global" assets in the design studio (IE Thank you pages, global forms, etc).
Hope that helps!