If you want to use the Digital Publishing Suite product (our product for the last five years or so) then you need to use InDesign CC 2014 or earlier. The new Digital Publishing Solution product, which goes live next week, runs on InDesign CC 2015 (as well as earlier versions).
You have to purchase a license to DPS. The first link I posted above provides information on how to get pricing. As for learning how to use DPS, we have a wealth of information at Digital Publishing Solution Learn & Support, including a complete getting started section.