Where's Astro is a bite-sized LWC application that covers properties, decorators, fetching data with Wire Service & uiRecordApi, component communication using Custom Events & pubsub, and how to work with third-party JavaScript libraries.
Run ./scripts/createOrg.sh (if on a Mac) or cut and paste its commands and run them individually (on Windows) to create a scratch org. It assumes you have already set a default dev hub.
Once you're in the scratch org, open the "Where's Astro" flexipage in the Sales app.