Perform the same action on every sheet. Edit the second Subroutine to customise
Sub SheetsFormatter()
Dim ws As Worksheet
For Each ws In ActiveWorkbook.Worksheets
Call action(ws)
Next ws
End Sub
Sub action(ws As Worksheet)
ws.Rows("1:1").Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
ws.Cells(1, 1).Value = ws.Name
End Sub