If I encrypt a file with
gpg -c file.zip, and change the filename. Is there any way I can restore the filename as I used as a password. or the name encrypted to?
The gpg man page documents a few relevant options:
This overrides the default, which is to use the actual filename of the file being encrypted.
This defaults to no.
Usually there is no way to recover the old filename. If you change the name of a file, GnuPG doesn't know about this. Maybe you have backups and can recover the filename from there. Or you have to try to remember what the name was.