Where's is the old laptop? Sync isn't a backup and if you log off and back it will not remain if you have no longer have the old laptop. What you need to do is use the Firefox backup help to backup the profile and bookmarks and data and transfer that to the new computer insuring it wont get deleted or cleared from sync. And sync isn't a backup system it just sync data between one Firefox browser to another Firefox browser on the same account. But to keep the data on the new you should really move that data over to keep it safe on the new computer.

And sync isn't a backup system it just sync data between one Firefox browser to another Firefox browser on the same account.

It Syncs to a Sync server which is why if you change your password it deletes the synced information since the connection is encrypted by the password.

I just purchased a new lap. I am unable to sync the new laptop to the old laptop.

If you can manually get your Profile(s) from your old laptop then you can restore it on the new laptop perhaps. https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles