Normally the file is saved in a Turbotax folder, you may have inadvertently selected a different folder .
Do a file search for *.tax2023 to see where it may have gone ( the * tells it to search for any file with .tax2023 name)
As far as starting a new return, open Turbotax, in top left click on file and the dropdown menu will have an option that says "new tax return"
