Hi Sue,
Yes, it's perfectly normal to feel the way you do - I did when I first went with JY, as do most people. I'm doing the same tour as you, only on the 26th Sept. Not sure if our paths will cross at some point along the way, but if not, just relax and go with the flow and you'll have a great time. I did Canada and Alaska 2 years ago and it was brilliant.
Best wishes
Anne