I installed Halion SE 3 on a mac (Monterey) and there are no sounds available. I have no paid Steinberg products, only this free VST instrument.
I see the library directory in the installation DMG image, but where do I copy that folder and how do I configure Halion to find it?
HALion Sonic SE is just a player and comes with no content at all.
You can get some free instruments here:
You can also google some other free instruments.