Welcome. For starters, don’t give up. Audio can be a complicated process, with lots of different settings on different computers. But once you figure out what is going on, it will be smooth saililng.
Mac or PC?
Dorico and the audio engine are two separate processes. For starters, make sure you have restarted your computer after installing (not needed necessarily, but worth trying).
If the audio engine is hanging, you need to manually quit it using Task Manager or Activity Manager.
Someone from the team will weigh in soon, this is just a starting suggestion.