Read: Matthew 11
When Jesus had finished instructing his twelve disciples, he went on from there to teach and preach in their cities. (Matthew 11:1 ESV)
Jesus went on several large tours of the region around Galilee. He preached and taught about the kingdom of God everywhere he went. Traveling, preaching, and teaching were the practical means by which he communicated the purpose of God.
Jesus recruited men from all over Galilee. Men of all different backgrounds, probably from cities and villages of all different backgrounds, and then he travelled to their various cities preaching the kingdom of God. In some way I believe he was strategically modeling for them how to reach their own people.
Several instant images that come to mind when I think of the word tour. There is the kind of tour you need a guide for. It means stepping into unfamiliar territory and having someone explain your surroundings. For some of the disciples that's exactly what Jesus did.
There is also the kind of tour where you travel a previously determined route. Musicians, authors, and many other creative outlets use is kind of tour in order to help maximize the amount of people connecting with their work. I believe that's why Jesus went on his various preaching tours. He was going to strategic places of maximum impact. He was influencing in a way that would forever change the course of history, and it did.