as long as you eat something fairly simple on the day of the race you'll be fine... ideally focus on carbs (porridge, weetabix, wholemeal toast with jam, banana), with perhaps a little protein if needs be, but avoid anything heavy and/or fatty. As for the days leading up to the race, a higher carb intake is desirable to ensure you glycogen stores are nicely topped up

Complex carbs obviously are preferential (Wholegrains etc)
I try to avoid drinking anything in the 1hr leading up to the race or it leave me needing the toilet loads when I should be getting to the start line, and sometimes during the race as well, which is never ideal.