Thanks, Sims3lover. There are no restrictions on travel. My sims didn't travel because I've had so many problems with the game running slowly in the travel destinations and other bugs, that my sims rarely go anywhere. But if it works for you, by all means go ahead. I think travel could be incorporated into the story in a very interesting way.
And please feel free to start with whatever age you want. Again, changing the age of the initial characters - anything from teenager to elder - makes for interesting variations in the story.