Canada and the Rockies question

So I am 17 currently. I am about to enter my senior year in highschool and it is time to start planning for my senior trip. Living in Louisiana, there are many people who revolve their lives around alcohol. The vast majority of seniors head to the Bahammas or Florida or Cancun for a week. I do not wish to join in a week of drunkeness. I google searched for a backpacking trip across Europe a few weeks ago. It brought me to this site. I started looking around and quickly took interest in the Canada and the Rockies package. I have researched all of the places visited and I have decided that this may be some of the most beautiful areas in the world. I was reading about the events that occur during the trip and it brought up a few questions.

I was considering going on a tour with roughly 3-4 of my friends who will all be seniors as well. Is it ok that we go in groups on these tours?

We aren't the kind of folks who want to go to bars and clubs at night really and I have read that there is a lot of free time. Once we are stopped for the night, is there other things to do besides clubbing? Drinking isn't on our priority list.

Is this an enjoyable trip for 18 year olds?

I have always wanted to see this type of landscape. Where I live, it is flat terrain EVERYWHERE and trees. I researched some of the lakes and national parks that we would visit on the tour. During the months of May-August, is the water in the lakes swimmable in? I am not sure about how the climate is in Canada as it is hot here year round. If anyone would just like to answer some questions for me I would appreciate it greatly.

I really want to see this part of Canada but I am unsure if it will satisfy our desires for a trip.

Thanks,
Justin