Code to Get Current User

 Add a hidden parameter Report_User

Add custom code:

Public Function GetUser() as String

Try

return Report.User!UserID.ToLower()

Catch

Return "sqllogin"

End Try

End Function

Show Heading on Every Page

Click the glyph on Column Groups and select Advanced

Click the first (Static) row under Row Groups

Set Other Properties:

DataElementOutput: Auto

FixedData: True

hideIfNoRows: False

KeepTogether: False

KeepWithGroup: After

RepeatOnNewPage: True

SSRS Expressions

https://docs.microsoft.com/en-us/sql/reporting-services/report-design/expression-examples-report-builder-and-ssrs?view=sql-server-ver15 

Fill / BackgroundColor for row in tablix:

=IIF(ROWNUMBER(Nothing) MOD 2, "#ADD8E6", "#FFFFFF")

Expression for File Name:

@[User::ExportPath] + "FILENAMEPREFIX_" + (DT_STR,4,1252)DATEPART("yyyy",GETDATE()) + RIGHT("00" + (DT_STR,2,1252)DATEPART("M", GETDATE()), 2) + RIGHT("00" + (DT_STR,2,1252)DATEPART("dd",GETDATE()), 2) + ".csv"