LogicHound

   if (date is { Month: 10, Day: <=7, DayOfWeek: DayOfWeek.Friday }) { ... }

    static bool IsFirstFridayOfOctober(DateTime date)
    {
        return date.Month == 10
            && date.Day <= 7
            && date.DayOfWeek == DayOfWeek.Friday;
    }

    if IsFirstFridayOfOctober(date) {
       ...
    }

    if (customer != null)
    {
        customer.Order = GetCurrentOrder();
    }

    if (customer is not null)
    {
        customer.Order = GetCurrentOrder();
    }