First of all, good on you for giving it a go. That is the best way to learn.

Try using this approach. Delete everything you have got and use this code. You should be able to work out how to expand from here
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
    Select Case Target
        Case Is = Range("C35")
            If Proper(Target.Value) = "Yes" Then Rows(36).EntireRow.Hidden = True Else Rows(36).EntireRow.Hidden = False
        Case Is = Range("C43")
            If Proper(Target.Value) = "Yes" Then Rows("44:48").EntireRow.Hidden = True Else Rows("44:48").EntireRow.Hidden = False
    End Select
End Sub