AP and XP are earned points in the community. XP is the point type that determines your rank (more XP, higher the rank). AP is used to purchase any product on the site.
Go to “Hub” on the left sidebar. Enter the information on the submission form and select the contest you’d like to enter, then submit.
AP or “Audular Points” can be used to buy any merchandise on the site. That includes everything available in the shop.