transferring all my data from an old Macbook pro to a new one, --11 years apart.

Hello Prima,

Congratulations on your new Mac! As long as the new Mac is running the same or higher version of macOS as the old Mac was when the backup was created, there shouldn't be an issue. Restore your Mac from a backup covers steps to restore your backup using Migration Assistant.

"Use Migration Assistant

1. If you need to reinstall macOS, do that before continuing. For example, if your Mac starts up to a flashing question mark, you need to first reinstall macOS.
2. Make sure that your Time Machine backup disk is connected to your Mac and turned on.
3. Open Migration Assistant on your Mac. It's in the Utilities folder of your Applications folder.
4. If your Mac starts up to a setup assistant, which asks for details like your country and network, continue to the next step, because the setup assistant includes a migration assistant.
5. When asked how you want to transfer your information, select the option to transfer from a Mac, Time Machine backup, or startup disk. Then click Continue.
6. Select your Time Machine backup, then click Continue.
7. Choose a backup and click Continue.
8. Select the information to transfer.
9. Before clicking Continue, learn what it means to transfer a user account. In the example pictured here, John Appleseed is a user account. If an account on the your Mac has the same name, Migration Assistant asks whether to rename or replace:
   1. Rename: The account on your old Mac will appear as an additional user on your Mac, with a separate login and home folder. 
   2. Replace: The account on your old Mac will replace the identically named account on your Mac.
10. Large transfers might need hours to complete, and might seem to pause occasionally. You might want to start in the evening and allow migration to complete overnight. Click Continue to start the transfer. 
11. After Migration Assistant is done, quit Migration Assistant, then log in to the migrated account on your Mac to see its files."

Cheers!

Yes, but:

The new machine may require different adapters for physical access to the old drive. if you are stuck, USB-2 speeds are as fast as most rotating magnetic drives.

Remember that the simplest time to bring forward your old info is at FIRST RUN. It will ask you to create a new user -OR- to tell it where the current User account can be found.

...at that point, you tell it to use your old Time machine drive.

AppleCare for iPhone is country specific.

AppleCare for Macs is supposed to be world-wide.