What should i wear ???!!!???!!!?

ok well i usted to go to this one skool that went from kindergaten to 8th grade and i swithched schools at 5th and went to a different skool for 6th 7th and 8th well tomarrow there is this thing and all the people from my old skool are there and i want to make a good immpression and since some of them havent seen me since like 5th grade, what should i wear????