Install LrC presets on a new MacBook Pro but I cannot access my old laptop/LrC catalog - help!

P.S. External Editors (Plug-ins)

While you are inquiring about presets, you might also have an issue with External Editor Plugins. For example a DxO NIK plugin. Typically the easiest way to fix those is to simply reinstall the particular software (the install should install the PS and LrC plugins) . Mind you, some (few) software installs those plugins via a menu command within the app (the ones from SKYLUM come to mind)

My old Mac is dead. 

• I wonder if the Apple Store Techs can recover the data on the old hard drive, copying it to an external drive?
• And I see that on the WEB, their are videos on the how to.

I cannot migrate anything from my current LrC catalog.

• So, from that I assume that your LrC catalog is on the internal hard drive on the dead MAC?
• Or was it on an external drive?
• And did you keep a backup (not in the internal drive)

 have my presets saved in a folder on my new Mac

That and the rest of your description brings up a point for the future. What is backed up via LrC backup. The .lrcat, and the .lrcat-data files. And not the Presets, Preferences, Plug-ins, Photos, etc.

see:

You're Probably Not Backing Up All of Your Lightroom Classic Data | Fstoppers

Which Lightroom files do I need to back up? | The Lightroom Queen

How to manage backups as a photographer using the 3-2-1 rule | simonwiffenphotography

> I have my presets saved in a folder on my new Mac.

You should be able to import your presets via the Presets context menu as shown on attached screenshot