Save only the Activesheet as a new file

Maybe:

Sub Broobi()
    Dim SaveName As String
    
        SaveName = Sheets("Lookup").Range("C35").Text
        ActiveSheet.Copy
        ActiveWorkbook.Sheets(1).Name = "Sheet1"
        ActiveWorkbook.SaveAs FileName:="S:\Services\·Section-Wide Data\MASTER DATA\MyFile\" & _
           SaveName & ".xlsm"

End Sub