if you want to create a new wallet then follow these steps

first of all close bitcoin core
go to C:\Users\Username\AppData\Roaming\Bitcoin
in this folder you will see a file named wallet.dat
first you take a backup of this(copy it to a safe place)
now either you rename it to something else or remove it

now open your bitcoin core wallet and it will create a new wallet at startup


if you are asking about how to get your password back then forget about this