Defining where you want to go sets a goal to work toward. A lot of people talk vaguely about travel.They never say where they are going, just that they are going. Picking a destination is immensely important, as it gives you a definite goal.
How much does it cost to travel? I have no idea without knowing for how long you’re going away. You can’t figure out how much you need to save if you haven’t decided on how long you’ll be in your destination.