Welcome to the RTA Forum!
It sounds like you've got quite the epic trip planned.
How much time do you have for this trip, and how much money do you expect to have in your budget? I assume you'll be driving back to Nashville when you're done.?
Campgrounds typically cost around $20 a night, and barebones motels will generally run around $50 - although in both cases there will be some higher and lower spots. The California Coast and Canada are both places where costs will typically be higher.
The "bible" for driving to Alaska is the Milepost, and that will provide answers to just about every question you could have about driving to Alaska. It's a book you should really pick up ASAP. If this will be a round trip, you might also look at taking the Ferry (Alaska Marine Highway System) from Washington or British Columbia to Alaska.
I would strongly recommend you take the Roadtrip Compatibility Quiz. If you can't agree on tents/hotels, there's almost certainly other things that you aren't seeing eye to eye on, and the quiz will help you figure things out now, rather than arguing about them on the road..