I keep getting an error that I have too many datasets.

What version of Quicken are you running?  (Help > About Quicken).

If you are not running R33.24, I suggest you update your Quicken installation (Help > Check for Updates) or download and install the Mondo Patch (https://www.quicken.com/support/update-and-patch-20182019-release-quicken-windows-subscription-product).

Once updating is completed, try File > Copy or Backup File > Create a copy or template (under Advanced Options).  This should create a copy of the file with a new dataset ID.  If this resolves the error message you have been getting, use this new copy of the file as your main file going forward.