I have a week till my pilgrimage to Rome !

This time next week I will be panicking and packing my suitcase for my trip to Rome for the 5th of March.
Well, its a pilgrimage since I go to a catholic school + the trip is mostly for 'cultural' and 'educational' reasons but COME ON
ME AND MY CLASSMATES ARE GOING TO ROME
R O M E
BY PLANE
I really doubt that, no matter how harsh it sounds, that finding ourselves will be the main concern on this trip because a, we're going to an airport and going on an airplane together and b, we're going to be in a foreign country without our parents.
We are going for five days and get to go anywhere and everywhere (within reason) but obviously we have to go to Vatican City, St Peters, The Sistine Chapel e.c.t. but we have choices to do touristy things as well,
GAH I'M SO EXCITED!

What I really wanna know is; who here has been to Rome?
♦If you have, what do you recommend we do?
♦Whats the best places?
♦What places should we avoid?
♦Any other info we should know?

Thanks! :)