It’s really just:
- Download the installer app
- Start the installer app, insert USB stick into Mac, click Create macOS Installer and choose the USB stick
- Start another app and click button to choose what you want to do (i.e., Build and Install OpenCore)
- Reboot Mac and start from the inserted USB stick
The instructions are step by step with pictures, it’s not more difficult than installing Roon ROCK (I’d say less difficult) and everyone managed that.
But up to you, a Nucleus One or new Mac Mini is also nice 