buzzman

you may get the help you need in the touring forum or living car free forum. As far as long distance touring and avoiding main roads and using back roads, dirt roads and trails it would be possible with a good mountain bike set up for touring- possibly with a bob trailer rig off the back.

I started mapping a route that went from Western MA up through VT to the Canadian border using logging roads, fire roads, dirt roads and trails with very few sections on paved roads or highways just to see if it was possible. It would take some work (research and really good maps), mean a lot of miles and way more climbing than you might do otherwise to tour in this fashion consistently- but it could be a lot of fun and give you an amazing perspective of North America.

If you've never ridden a bike before and are literally starting from scratch then a mountain bike might be an easier bike for you to ride anyway. You can drop the seat all the way down and you'll be able to easily put your feet flat on the ground, the wider tires, upright style bars and frame geometry also makes the bike easy to handle for a beginner.

and it doesn't sound like you're a rider that's necessarily interested in speed and so, again, a mountain bike set up for touring might do the trick.

edit: you might check the mountain bike forum too. since your question involves off-road riding.