Where do I control the social sections, like the Monthly Quiz?

In your site's CMS, open Settings, then the Social tab. It holds the defaults for the TikTok and Instagram side of your site; turning Monthly Quiz off hides every Monthly Quiz section across the site at once. The same tab sets the two figures at the top of your posts page, each chosen from a list: your top topic, posts in the last seven days, the week before that, your total, this year's posts, how many topics you cover, your latest post, the year you started, the split between Instagram and TikTok, your busiest month, a typical month, or nothing at all. Anything that cannot be worked out from your posts is left off the page rather than shown as a zero. The most-viewed post panel above the wall has its own switch there too. With several channels, Quizzes & Games' Automation Config tab also offers One Combined Quiz: one set shown site-wide, its questions drawn from every channel's current quiz. The Channels tab next to it governs only show channels (YouTube, Apple Podcasts, RSS feeds), and how each social channel plays its videos is set per channel in Dataweaver.