I also use a headless Mac Mini running the Roon Core, and when needed (e.g. rebooting it occasionally) I just use screensharing from my MacBook Pro which is my main Roon control device. As @Grant_Johnson said, you’ll need to set it up out of the box with a monitor/keyboard/mouse. I believe an iPad can also be used but IIRC it needs 3rd party software.
I’m currently running my core on a windows 10 laptop i have a mac mini that I don’t really use much I’d like to move my core to the mac mini in a dedicated listening room but I’m not sure on the best way to set it up for music use only I would like to use the mac as the core connected to a thunderbolt HDD to my chord hugo dac to kef ls50 wireless speakers am waiting on the new iPad to be released which I would use as my control device
My mac is a late 2014 model running high Sierra but i have a apple tv 3 I could possibly use to mirror mac screen would it be better to use the mac as a roon sever or bridge as I’m not entirely sure the best way to set things up
Connect your MacMini to your Wifi network (you probably already do).
Have your music files installed either on the MacMini hard drive, or on an external SSD connected to the MacMini via USB or Thunderbolt.
Install the Roon app on the MacMini.
Follow the Roon instructions.
As mentioned previously you will need a monitor/keyboard/mouse or another Mac computer mirroring your MacMini screen to accomplish these tasks. You may be able to do this with an iPad running a VNC app, but I don’t have experience this approach.
Like you, I use a Mac Mini as my server with Roon Server installed and I control Roon via an iPad with Roon Remote installed.
Occasionally i need to access the Mac Mini for some settings & so on, I use Duet (https://www.duetdisplay.com/) which allows my iPad to become the screen of the Mac Mini. With the latest release, it can even be achieved wirelessly. It has served me well so far, highly recommended.
Required a bit of configuration setup but after it’s set, it’s all good. To be installed on both the Mac and the iOS device, there’s a small subscription to unlock all features.