LR Classic CC-LR CC and Sync'ing Between Desktop and Laptop

I am brand-new to Lightroom. I'm not quite sure of the conceptual framework surrounding photo-editing in the same photo archive with 2-different PC's and synchronizing the two PC's.

BACKGROUND:

1. I have the latest versions of LR Classic CC and LR CC installed on both my desktop PC and my laptop PC (both Windows 10).

2. I have imported my existing photo archive folders (about 21K images) from my MS OneDrive to LR Classic CC on my desktop PC.

3. I have completed initial face recognition on the archive in LR Classic CC on my desktop PC.

4. I have begun assignment of keywords to images.

5. I have created LR "collections" and "collection sets" in LR Classic CC on my desktop PC.

6. I have "Start[ed]" sync'ing to LR CC on my desktop PC.

QUESTIONS:

1. How does LR Classic CC on my laptop PC get updated (sync'd) with my desktop PC folders and collections and keywords?

2. Do I turn "Start" sync'ing LR Classic CC with LR CC on my laptop PC? When I do that I get two messages:

     a. On my desktop PC that I need to "pause" sync'ing" on my desktop PC;

     b. On my laptop PC that switching sync'ing with LR CC between two catalogs can cause unanticipated results.

BOTTOM LINE QUESTION: I suspect I'm missing something fundamental, conceptually or otherwise. Please draw me a word picture of the correct process for sync'ing between two PC's with editing capability in LR Classic CC.

Thanks,Rod Michael