Some info about things like your current activity levels would go a long way towards helping people provide useful comments. For example....

When I did my first tour, cycling was a part of my daily life. I rode for sport, fitness and for transportation. As such, I didn't do anything outside the ordinary to get ready for the tour, which ended up lasting nearly 4 months and covering some 6,000 miles, other than take one 62 mile ride with the bike fully loaded, and a few sorter rides partially loaded, in order to get a feel for handling. So I would say you don't need to do anything extraordinary. Just ride like you would if you were not planning to tour.