After you file

Don't know about your  first question.   But if you use the Desktop program anything  you do or don't do in your Online account won't affect your desktop returns.   Your returns and data are only stored on your computer.  Yes your previous year tax return will transfer into the next year.  Make sure you have the .tax2023 or .tax2024 data file on your computer to transfer into 2024 or 2025.