I want to follow a new Area 51 beta to make sure it goes well, but I can't find an RSS feed for new questions. There is one for specific tags, but not for all questions.
Please provide such a feed.
There's a feed for recent questions. Just use the site's URL in your RSS reader. For example, if I wanted to follow the question feed on Software QA, I'd plug https://sqa.stackexchange.com/
as the feed URL.
It's also linked at the bottom of the front page, below all the questions, as "recent questions feed".