OK, here's the thread about the Trans-Canada Trail:
http://www.bikeforums.net/showthread.php?t=546765

So, first of all you might want to rethink your basic plan of riding the Trans-Canada Trail.

Secondly, just get a bicycle and start riding now ... outside. Pick up some inexpensive cycling clothing and gear to try. Attend a bicycle maintenance course or two. And visit your local grocery stores to see what kinds of food they have available. Then go ride! Start with regular shorter distance rides, and build up to longer distances.

Once you get out there and get riding, you'll discover that you might want better cycling shorts ... or a different saddle ... or a different panniers ... or a different bicycle all together. But you'll never know that until you get out and see for yourself.

Find a club in your area ... one that either specializes in cycletouring, or has a strong cycletouring division, and go on rides with them over the next year. You'll pick up all sorts of tips and tricks along the way.

And don't forget to do some short weekend tours to sort out what you need to have along, and what you can leave behind. These also help with things like learning how the bicycle handles with the weight of panniers on.