you are asking a very beginner question and with just a little bit of experience you should get to your answer yourself
basically you pass a date value into DateFormat() function. Now() is a function returns a date value
if you want to pass a date value into DateFormat(), it is just DateFormat( any_date_variable, “mm/dd/yyyy” )
that “any_date_varible” is a date value, it can be something like:
“2022/01/20”
createDate(2022, 01, 22)
someQuery.DateOfBirthColumn
If you don’t know what a date value is, or how to create one, you simply just don’t have enough understand of this langue, do some more practice you should get to it with no issue