This is probably a question I should have asked before the transfer started. Are the files that are being transferred to the new machine still going to be on the old machine, I hope?
If you are using Windows Easy Transfer, it moves user files. I don’t recall an option for copying with that method. However, you can copy files manually between shared folders over your network if that is a concern. Using the Easy Transfer lets you keep settings for appearance and setup, which is not possible with manually copying data files.
That depends on how you copied them. If you used the copy/paste functions, they will still be on the old machine. If you used the cut/paste or move functions, they will not be on the old machine.