Hey, you don't need to install or user neither docker nor dockage/portainer etc. HexOS takes care of everything for you.
All you need to do, is login the HexOS Dashboard, go to curated Apps and install all the apps you want and need and HexOS is taking care off everything. No docker compose files, not folder mapping, no db user/PW to take care off, just super simple one click install apps.
Under the hood HexOS is configuring and running those apps in docker, but you absolutely don't need to worry about this yourself.
Just give it a try and install the apps and please report back how it went :)