Yeah, we know all about how to book flights and find hotel rooms. That stuff's boring anyways, so we won't get into it. What you really need to think about is how you're going to accomplish this adventure by walking. Seriously, are you ready for it? If you had to get up from the computer right now and hike up some peaks in Italy could you do it? Would you have to tap out after an hour? Don't let your adventure turn into you snapping pictures of the backs of everyone going ahead without you. It's your adventure, so get ready for it. If you need to workout, do it. Prepare for this journey so you can make the most out of it.
After you've gotten yourself physically ready, you need to plan the way. What type of terrain, climate and scenery do you want to experience? Some adventure walks are planned out for you so you may not have as much leeway on this. But if you're planning this trip yourself then you'll need to map out where you're going, how long it will take, where you can rest, where you can eat, and what the weather will be and all those fun little details.
Remember, planning isn't the enemy of adventure. If you take a short time to plan ahead, you'll reap the benefits when you're on your adventure by experiencing everything you choose to.