Need the proper syntax to use Case/Select Case in vba properly.

Try this, but note this isn't the usual way to use Select Case.

    Select Case True
        Case Left(Cells(Row, Column), 4) = "Port" And Cells(Row, Column - 4) = ""
            DeviceType = "lightweight"
        Case Left(Cells(Row, Column), 4) = "Tecr" And Cells(Row, Column - 4) = ""
            DeviceType = "standard"
        Case Left(Cells(Row, Column), 4) = "Port" And Cells(Row, Column - 4) = "TEST"
            DeviceType = "TEST lightweight"
        Case Left(Cells(Row, Column), 4) = "Tecr" And Cells(Row, Column - 4) = "TEST"
            DeviceType = "TEST standard"
    End Select