I'm biased, but I think Australia offers the greatest opportunity for great travel experiences. Language is not much of a problem, they do claim to speak English, lots of good transportation, and a huge variety of experiences. Get out of the cities to see the real Australia. Another place I was very impressed with was Costa Rica, but I haven't been there since the early 1980's and I understand it has become much more developed. If Europe is your interest, just pick a country/city and explore. Not all tourist destinations are bad. There is much to learn in cities such as Rome, Florence, Nice, Paris, etc.
Travelling is as much of a learning experience as you want to make it.
 

Another thought. Cuba is an interesting country to visit. My favourite place in Cuba is Havana. The "old city" is very interesting, and Cubans are very hospitable.
 

Question: How young are you? Are you old enough to travel on your own?