I'd like to scale and I'd advice where to look for further learning material and best practices how to do this with docker.

I have a more high level docker question. I currently have one dockerized app running on a custom server with dedicated DB container. This was more or less my learning project and a POC of the app. Now I'd like to scale and I'd advice where to look for further learning material and best practices how to do this with docker. I imagine it would be best to have the same APP/DB container par for each new customer. Am I right?