How do I use migration assistant to transfer files from an External Hard Drive (that has been used with a PC with Lightroom) to a new MacBook

You should be able to copy over folders and sub-folders to a Mac-formatted drive, no problem.

You want to put the Lightroom catalog and cache files on a fast drive (like the internal SSD). Full-size photos can go on a Mac-formatted external hard drive.

I'm guessing (hoping) that there's some way in Lightroom to point it to the top of the copied folder tree (and have it take care of fixing up all of the references) instead of having to tell it where full-size photos moved, one by one.

But note that if the existing drive is formatted using NTFS, the Mac will be able to read it, but won't be able to write to it. Out of the box,

• Windows and macOS can both read and write FAT32 and exFAT
• macOS can read (but not write) NTFS
• WIndows cannot make heads or tails out of HFS+ and APFS at all

this is the official word, but as you can see, it require the entire PC, not just its drive:

Transfer from PC to Mac with Migration Assistant - Apple Support

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scott99lee wrote:

I don't know what format the EHD is, but it has photos imported through a Windows 11 machine and I want to transfer them to my new MacBook Pro with current Ventura OS. I'm trying to do this with Migration Assistant

Why not just connect the external drive to the Mac and copy/move the files to your Mac?

scott99lee wrote:

From what I read because it was from a windows machine they had to be converted first. I did try just plugging it in and some were "visible" and some weren't.

Sorry but I'm not sure what "some were visible and some weren't" means. Macs can read Windows formatted external drives. Just connect and copy the files over.