Linux navigation, beyond basic use (system config, coding, etc.), troubleshooting, self-reliance, confidence.

Wiki user/group management, addons, themes, etc.

Setting up out-of-the-box platforms on VPS, plus analysis. (ie. To set up a PeerTube or Invidious instance I'd want to keep an eye on bandwidth and such so I don't get a huge bill.) Then customization.