Had to choose between Console streaming (preview) or mixer.

yes it really all depends how you are trying to stream you can stream mixer and twitch straight from your xbox you can even plug a webcam into your console to show yourself on stream the downfalls of streaming on console is that you cannot have any type
of alerts on or a green screen but if your just starting out you wont need all that anyway and i would choose mixer in your case because its very simple to stream and you can do co-streams if you are on seperate consoles and mixer provides so many futures
the only gear you would need is a good headset and webcam

Sorry to hear it. I've had this same issue with my mixer streams. It's not you or your console though. Sometimes you need to refresh the stream page a couple of times for it to come through.

I haven't played it yet, but may I give you a general suggestion?

A great way to understand if you may like a game or not is watching at gameplays and more on Mixer. I have lots of fun with the live streams, but I admit I also use it as a valuable way to help me choose between games.

I find it easiest to just stream straight from console on mixer. Don't stream a lot but trying to get more into it and mixer works great.

We can't know what the upcoming Xbox Series X features for streaming are just now.

Microsoft had their own streaming service called "Mixer", that they shut down just yesterday on July 22nd. And for that service, they had streaming built right into the Xbox One console. You'd just set up your stream from the console guide, and could stream
to Mixer.

Twitch has made a separate app that you could install on your Xbox One, and set up streaming to Twitch from the console.

Unfortunately for YouTube, there was no app or built in support, as YouTube/Google hasn't provided such an app on Xbox.

If you really want/have to stream your Xbox gameplay to YouTube, the currently only known way is to have a PC with HDMI capturing hardware and a streaming software like OBS or XSplit to stream that video capture from the PC to YouTube.