I did rubbish today help please ?

i had a pretty rubbish day today, i'm trying to lose weight by the way. See for breakfast i had a banana sandwhich (240 cals) and for lunch i had a tuna baguette and a flapjack but i don't how many cals they were, it's from school so they make it as healthy as possible xD and yeah for dinner....macdonalds, which was only 450 cals. I can't exercise today but i have alot planed for tomorrow so if i eat 1100-1300 tomorrow all healthy foods do you think i can cancel today out? thanks! :D