Autosave is usually available after a crash. And after any edit changes have been made, VP should prompt to save when it's closed. Save Project File AS routinely, giving it a unique # or name, so as not to overwrite prior saves. Using Save Project Files (no AS) will overwrite. To access Save AS, click the chevron to the right of the SAVE PROJECT button on the Home toolbar. Never move or delete source files until the project is complete.
Look for the autosaved file in C:\Users\[user name]\AppData\Roaming\NCH Software\VideoPad. Search the PC for other VPJ files.