Is this your first Alaska adventure? If you are, you are in for and awesome trip. My wife and I decided to take off in 2015 and started off by ourselves. Figured what the heck. Made it halfway through Canada and had met, then re-met and re-met people on their way to Alaska. And everyone of them were enjoyable to meet.
The previous comments/suggestions are all excellent. You will find and meet some really great people and see some amazing sites. And there are some others over on Roll Call 2017 you might want to checkout for info.