Here are some travel tips I made for a young (15 yr old) girl travelling to Europe for the first time (a summer trip to Italy and Spain in her case). She was also travelling with a small school group. Its a bit long, but here goes:
Make two copies of your passport, ticket, medicare card, travel insurance, debit card and credit card, if you have one. Leave one copy at home with your mom, pack the other copy in your suitcase (black out the expiry dates on any credit cards). That way you will have the information you need if you loose any of these things.
You absolutely MUST use a moneybelt at all times, from the moment you leave home. There are pickpockets everywhere in Europe - on the streets, in airports, on trains, in museums and cathedrals, and they are very, very good. Never carry more than that day's spending money in your purse or pocket and always keep your debit/credit cards and the rest of your cash in your moneybelt. My mom and my dad - both very careful and experienced travellers - have been pickpocketed (in Spain and Italy, actually) and I had my purse stolen in Athens, but because the bulk of our money and our credit cards - and our passports if the hotel didn't have a safe -were in our money belts, none of us actually had much stolen. (There are moneybelt thingeys you can wear around your neck under your shirt as well.)
You can do advance check in online, 24 hours in advance of your flight. But if you are travelling as a group maybe your leader will do this.
If you have any liquids in your carry on bag, they can't be more than 30ml each and you have to put all of them into a ziplock bag to be screened separately when you go thru security. Include lip balm, lipgloss and stuff like that too.
Get some euros in advance from your bank, in small denominations. Once you are in Europe it is easy to get more from most ATMs with your debit card.
Prepare a currency conversion card (like on an index card) comparing Euros and Canadian dollars so you'll have some idea of what things cost in Canadian funds.
Take a bunch of ziplock bags, sandwich size and the large size. These come in handy for bringing a snack with you on day trips (sneak something from the breakfast buffet, if there is one) or for transporting damp laundry in your luggage.
You won't get fed on the plane from/to (small Canadian City to large Canadian City). Bring food (peanut butter sandwich, a banana or a couple of granola bars). Food - and everything else - at the airports is horrendously expensive. You will be fed on the overseas flight, and I believe this meal is still free. If you want to buy anything on the plane (unlikely) they now only take credit cards, no cash or debit accepted.
Pack a change of underwear and a Tshirt in your carry on bag just in case your suitcase is late arriving.
If you plan on touring any churches/cathedrals or especially the Vatican, many won't let you in if you have bare shoulders and some won't let you in if you are wearing shorts (tourists are the only ones wearing shorts). (The nearby vendors selling shawls do a roaring business.)
Stuff to pack that you might not think of:
travel alarm clock (also always call room service for a back up wake-up call if you have an early morning start)
used books that you can leave behind when you're done
notebook & pen - keep track of your purchases for your customs declaration when you return to Canada
ear plugs (great if you don't need them, but very good to have if you do. And they are tiny.)
hand sanitizer (purse size). Keep it in your carry on or day purse and use it constantly.
diarrhea medicine, like Immodium. You don't need the whole package, just a few.
advil or aspirin (just a few)
one of those little rain ponchos
a small cloth day bag for carrying purchases
facecloth (this is changing now, but many European hotels still don't provide them, you are expected to bring your own. Get some cheapies from the dollar store and just leave them behind.)
It is very hard to walk on cobblestone streets all day in flip flops. Bring proper sandals and good walking shoes (sneakers).
After you have packed your clothes, take half of them out. Really. For one thing, you are probably going to want to buy some clothes while you are there and you are going to need room for them. Also, it is easy to wash shirts & undies in your hotel sink. Wring them out as best you can, then roll them up in a bath towel and walk on them to squeeze out as much water as possible. Hang to dry.
For 10 days: one pair of jeans, one lighter pair of long pants, two pairs of city shorts (or maybe one pair and a skirt). 4-5 short sleeved shirts (ones that will dry relatively quickly), maybe one long sleeved one, but I doubt very much you'll need it. A sun dress, if you like. One long sleeve light jacket/sweater/hoodie for cool evenings (something you can tie around your waist when you don't need to wear it). Wear the bulkiest stuff on the plane (like the sneakers, the jeans and the hoodie).
Everything should easily fit in a rolling bag 23 cm x 40 cm x 55 cm (9 in x 15.5 in x 21.5 in) and your carry on bag - at least on the way over. (Getting everything home can be a bit more of a problem!) Don't pack a great big suitcase, you will really regret it, especially as it sounds like you're going to be moving around a bit.