Need some assistance with HomeAssistant audio

We threw out our Alexa devices due to privacy concerns (can’t wait to get wake word functionality in the HA voice assistant!) My wife wants to be able to play music! I need some help understanding the Media section in Home Assistant. From the reading I’ve done and the few videos I’ve found for setting up and configuring home audio, I’ve ended up more confused than anything. When I’m in the Media section in HomeAssistant, I can see things like Radio Browser, TTS, Local Files, etc. In the bottom corner, I see Web Browser, and I can see my Home Theater receiver, and my Chromecast audio speakers that I have set up. I want to be able to play music to these audio devices. I can choose the web browser and I can play radio and TTS just fine, but if I try to send audio to one of the other devices, like the Chromecast speakers, I get swirling circle for some time and an error in the event log that looks like this.

Logger: homeassistant.core
Source: components/cast/media_player.py:750
First occurred: 8:00:24 PM (6 occurrences)
Last logged: 8:41:38 PM

Error executing service: <ServiceCall media_player.play_media (c:01H1DBG8RMBZWFK11HED0F2WGG): entity_id=['media_player.livingroom_speakers'], extra=, media_type=audio/aac, media_id=media-source://radio_browser/52e142ff-1137-422a-b97e-75e27880abff>
Error executing service: <ServiceCall media_player.play_media (c:01H1DBK1TC4E5EC9G57M36TBR9): entity_id=['media_player.livingroom_speakers'], announce=True, extra=, media_type=provider, media_id=media-source://tts/cloud?message=Hello+Robert%2C+you+can+play+any+text+on+any+supported+media+player%21&language=en-NZ&gender=male>
Error executing service: <ServiceCall media_player.play_media (c:01H1DCAE6PNS26KBZ0GZE546GS): entity_id=['media_player.livingroom_speakers'], announce=True, extra=, media_type=provider, media_id=media-source://tts/cloud?message=Hello+Robert%2C+you+can+play+any+text+on+any+supported+media+player%21&language=en-NZ&gender=male>
Error executing service: <ServiceCall media_player.play_media (c:01H1DDV3KNF51S9QXFACFH6EZQ): entity_id=['media_player.livingroom_speakers'], announce=True, extra=, media_type=provider, media_id=media-source://tts/cloud?message=Hello+Robert%2C+you+can+play+any+text+on+any+supported+media+player%21&language=en-NZ&gender=male>
Error executing service: <ServiceCall media_player.play_media (c:01H1DDVPGWMD6SG8NZSKEFJX73): entity_id=['media_player.livingroom_speakers'], announce=True, extra=, media_type=provider, media_id=media-source://tts/cloud?message=Hello+Robert%2C+you+can+play+any+text+on+any+supported+media+player%21&language=en-NZ&gender=male>
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/core.py", line 1867, in catch_exceptions
    await coro_or_task
  File "/usr/src/homeassistant/homeassistant/core.py", line 1889, in _execute_service
    await cast(Callable[[ServiceCall], Awaitable[None]], handler.job.target)(
  File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 226, in handle_service
    await service.entity_service_call(
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 798, in entity_service_call
    future.result()  # pop exception if have
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 980, in async_request_call
    await coro
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 838, in _handle_entity_call
    await result
  File "/usr/src/homeassistant/homeassistant/components/cast/media_player.py", line 750, in async_play_media
    await self.hass.async_add_executor_job(
  File "/usr/local/lib/python3.10/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/local/lib/python3.10/site-packages/pychromecast/quick_play.py", line 78, in quick_play
    controller.quick_play(**data)
  File "/usr/local/lib/python3.10/site-packages/pychromecast/controllers/media.py", line 547, in quick_play
    raise PyChromecastError()  # pylint: disable=broad-exception-raised
pychromecast.error.PyChromecastError 

Can anyone give me some suggestions to get audio playing to any of my media devices so I can start to use TTS for announcements and also play music on my speakers? I can send audio to the speakers from other applications like Google Home. I can see what is playing on the speakers and home theater so I know the devices seem to be communicating with HA, just can’t send any audio from HA to the devices. Any help would be greatly appreciated! This forum is filled with a lot of talented users, and I appreciate them being willing to help those of us that get stuck from time to time.