>>984132>DR 650Solid choice.
First, wear your gear, dress for the crash, etc. Find what's comfortable, what works for your style of riding. Might take a few tries to find a setup that you like.
Second, know your moto inside and out. Ability to diagnose and manage repairs is huge when you're way out in the backcountry. When you're doing maintenance in the garage, work out of the toolkit you bring when you ride. Much better to find out you need a 17mm socket or T20 torx bit to do some procedure in the garage than it is when you're 40 miles away from anything and something broke.
Not real familiar with that bike, but go through and fix all the stuff people have issues with.
Know your limits, when to call it a day and get some rest. A little fuckup in a car might wreck a bumper or body panel, that same fuckup on a bike will be significantly more painful.
If you're doing the trip solo, share your ride plans with someone you trust and check in with them regularly, update your timetables/routes as things change. If something happens and you miss a check-in, someone can raise alarm and has a general idea of where to start looking.
