New MBP M4 Max - When to use Time Machine to transfer data from my old machine (2013 MBP)

If you do, you have NO bookmarks, NO passwords, NO email setup.

What's the rush. You know what bare MacOS looks like.

But if you just can't wait, I propose a compromise:

Create a new Admin account that has never existed before, and plan on using it as a spare, just for administration. That way, when you bring over all your old accounts, there will be no collisions, and far less drama.

sputacus wrote:

My external Time Machine hard drive from my old machine uses an USB-A port. Will any USB-A to USB-C work for the data transfer?

Pretty much any adapter or replacement cable that carries data. There are such things as "charging cables" that have only the 5V and ground pins connected. You don't want those. Also, it is possible for a cable to carry data, but to be rated for only USB 2.0 speeds. Cables or adapters that can do USB 3.0 (sometimes USB 3.1 Gen 2) are preferable.

What would you recommend?

The Apple USB-C to USB Adapter works pretty well. It runs at USB 3.0 speed (reference: About the Apple USB-C to USB Adapter - Apple Support) – would have been nicer if it was USB 3.1 Gen 2, for the price. I have a couple of these sitting in a drawer to use when needed with front-panel USB-C ports on a desktop Mac, and don't have any complaints about their quality.

There are many other ways of going between USB-A (USB) and USB-C (USB), including some that provide several USB-A ports in return for the single USB-C or Thunderbolt host port that they consume.

If you have a portable drive with a Micro USB 3.0 B socket that came with a Micro USB 3.0 B to USB-A cable, you can get third-party Micro USB 3.0 B to USB-C cables that cut out the need for a separate adapter. There are any number of these (e.g., https://www.amazon.com/s?k=micro+usb+3.0+b+to+usb-c+cable).