Welcome to Outdoor Action. OA can provide backpacks and sleeping bags if you requested those on your application.
You will need to bring personal equipment. By now you have received an Equipment List explaining what you need for your trip. In order to help you gather what you need, Princeton has set up a number of online-only discounts with companies to assist you in purchasing low cost items that will meet the needs of your trip. The specific instructions for how to activate your discounts are available on the Orientation website.