Moving Lightroom classic files

The simple answer is that the files should go exactly in the same place on the new computer as the old computer. If the files were in My Hard Disk\Photos on the old computer, that's where they go on the new computer. If that's not possible, then follow the instructions at the link given by @Rob_Cullen 

You would do well to read the information at-

Move Lightroom to a new computer? | The Lightroom Queen

Note there is a comprehensive eBook available on the subject of moving.

Basically you need-

1) The photo files copied to the new system - in the same folder hierarchy.

2) The Catalog parent folder that contains the .LRCAT catalog file - copied to the new system.

3) After installin Lightroom-Classic, Open the catalog on the new system (by [Double-Click] on the .LRCAT catalog file.

4) Re-link the catalog to the image files, as suggested in the article link above- Step#6.

I moved a catalog from Lightroom classic to an external hard. I want to move it to a new iMac. My question is, I don't want to just copy it to the desktop, there must be a correct place to put these files so Lightroom will see them and open correctly. Thanks for any insight