CodeDamn is a large resources for learning front end web development, which is what's necessary for writing decentralized apps. Though the site is not specific about decentralization, it will teach you all of the technologies you need to know to write apps that run in a browser.
CodeDamn will not work without centralized DNS.
It will not work without central servers.
User accounts are not in the user's control. They're controlled by the service provider. An uncensorable and unstoppable monetization system is NOT supported.