Time travel to the past or future

Personally I would not like to travel in time, because I am a bit fearful, but if I had to decide whether the past or the future, I would prefer the past, because at a certain point it would take me to a reality that I know at least in textbooks, or movies, instead if I traveled to the future I could reach who knows what, a dystopian future or a perfect one, but I think it is a lot of risk. I would like to travel to the 70's but not in Chile, but in Europe, to be able to live the hippie movement in my own flesh, to enjoy the liberation of the bodies and the dogmas of the modern age, and to be able to live with those people. I think that the 70 ́s is the passage from the modern to the postmodern, and I would really like to know how that step was for those who lived it, and I consider it very interesting to capture a historical record of it. 

To be honest, I would not like to stay there, as I am afraid of producing some change in the balance of humanity, and I have seen a lot the movie "back to the future" so I think it would not be a good idea.