How come the album isn't showing any pictures in Lightroom when I created a collection in LrC and told it to sync with Lightroom?

Hi! A synced collection in Lightroom Classic should appear as an album with the same name in Lightroom, so please check these in order:

1. In Lightroom Classic, in the Collections panel, check that this collection itself is set to sync — right-click it and choose Sync with Lightroom, and look for the sync icon next to its name. Note: a smart collection cannot be synced; if yours is a smart collection, make a regular collection with the same photos instead.

2. Click the cloud icon at the top right in Lightroom Classic and check that sync is not paused and has finished.

3. In Lightroom, open Albums (not just All Photos) and look for the album with the same name, signed in with the same Adobe ID.

If the album is there but empty, please tell us whether the collection is a regular or smart collection and whether the sync icon shows next to it — that will narrow it down.