Deploy Rails 5 app

I developped an app with Rails 5. I have a HPE ProLiant ML350 Gen9 physical server on which I will install Ubuntu Server 16.04.4.

I also have a domain name bought on Gandi.

Could you please explain me the steps to do to have a working deployed Rails app ?

I seen a lot of tutorials, but I don't really understand what do I need. Do I need to do simple hosting ? or cloud hosting ? And what do I do with my physical server concretely ?

(Sorry, it's my first deployment ever)