Have you set up a MyDisneyExperience account? That is the first thing to do and that Disney site provides connections to buying tickets including the discounted and Gold APs for DVC members as long as you also have an online DVC account. If you are considering tickets other than an AP, I do not think there are currently any such tickets with a DVC discount, and you can buy them online through your MyDisneyExperience experience account or you might want to get a little discount and buy tickets through an authorized seller such as undercovertourist.com and link the tickets to your family members listed in your MyDisneyExperience account