> When I need to copy my Firebird database: Do I need to shutdown the
> Firebird instance first?

Yes. Becaus when you don't do that, the server may access the file
during your copy process and you would get a corrupt file copy.

> and If yes, what is the proper way to shutdown and startup it?

You can use the GFIX tool with the option

-shut full

to shutdown the database so Firebird will not access the file and

-online normal

to put it back online.

Examples:

gfix -user SYSDBA -password masterkey dbserver:mydb -shut full -force 0

gfix -user SYSDBA -password masterkey dbserver:mydb -online normal

> When I need to restart Windows Server, Do I need to shutdown the
> Firebird instance first?

No.

Best Regards

Stefan