I would say: Learn docker. This is the base deployment tool for Cloudron. No need to learn compose/swarm etc. Take some time to learn Heroku. Also see 12 factor app. A lot of ideas for Cloudron app deployment are inspired from these two PaaS concepts. Heroku can deploy lots of different frameworks/stacks, so just pick one you are comfortable with. And then the tutorial link above should be easy to follow. Without knowing 1 & 2, the tutorial can be hard to understand. Finally, there is lots of code at https://git.cloudron.io/box (looks for -app suffixed repos).