How much money do you think it will cost me to run away?

I have to get out of this place for a while. In the summer, I would like to run away. I am a young adult, so its not “running away”, but I’m feeling travel pangs. I need to escape my current life for a while; It would be about the length of the summer, or shorter. How much do you think such a trip would cost. and what other things should I consider? Also, I do not plan on bringing a car or flying anywhere, so my travel would just consist of walking, public transit, and hitching.