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If you erase the new one, that should leave it in the condition in which you purchased it. Amazon Renewed should be ok, but not to be confused with "seller refurbished" or sold on Amazon Marketplace by some third party, which is always asking for trouble.

Follow these instructions, despite the fact you are not actually selling it: What to do before you sell, give away, trade in, or recycle your Mac.

When it is finished, I recommend migrating from the older one's Time Machine backup, which will result it resembling the older one as close as possible. The setup assistant will prompt you for that choice.

After that, if you have newer files backed up elsewhere, copy them one by one to their respective locations in your Home folder's Documents, Desktop and so forth.

rebeccakw wrote:

Apple mid 2019 macbook Pro “renewed” from Amazon.

If I just wipe the new one and then copy the old files from my backup sources will that fix the ownership question?

Time Machine migration either during post-reset first boot and related setup, or performed later via Migration Assistant, will resolve file ownership issues, assuming you don’t next meet Activation Lock.

The usual way of transferring content to a replacement Mac is to use Migration Assistant, which will obviate those concerns. Besides, it's a lot easier than selectively copying documents.

Transfer to a new Mac with Migration Assistant - Apple Support

Did you purchase that Mac new? From Apple? The reason for asking is that you wrote it is running Sequoia. If that Mac was previously owned or configured, then correctly preparing it for sale prior to selling it would have been a fundamental prerequisite.

If your older Mac's contents are no longer available, or not useful, then there is no reason to create a backup of it.

Similarly, if the new Mac's contents are unusable for whatever reason, you might as well erase it, followed by populating its contents from whatever sources remain available.

You should still clarify whether you bought that Mac new from Apple, or from some other source.

If you “took over” an existing Mac without performing a re-install (or reset, on newer macOS versions), you’re just starting to see the issues, too. There are more messes awaiting, too.