Bandit,
We made the trip two years ago without an issue. Our biggest surprise was no firewood.
https://www.tripsavvy.com/what-can-i...canada-1481670 is one site you can use plus there are many others. Would assume you will buy a current Milepost which also has a lot of helpful info.
Found dealing with the Canadian border crossing was generally easier than the US folks going into Alaska or back into the US coming south. There are limits on alcohol, beef, fruits, pets, firearms, cash and others that you should be aware of. Was never checked at any crossing but answered all their questions honestly - thats when they took our firewood. You will need a passport or passport card to get back into the US but your drivers license is all that's required to get into Canada.
No need to take large quantities of food - it is readily accessible all along the way but we always had food for 5-7 days in the rig. Plenty of Walmarts and Costco. Brought about 20 lbs of fresh salmon back without an issue.
Its a great trip - take your time and have fun! We are going back to BC this summer but will wait another year before heading to Alaska again. You will meet lots of friendly people in Canada and Alaska. Bring a good camera.