Life is not a video game where you have control over everything in front of you with your fingers.
Once you step outside your front door by yourself, you are alone--no matter what your age.
Age gives you experience on how to adapt and react to unexpected situations and a 14yo., especially one who is not 'cittified', is not yet mature enough to be wandering alone.
Do a few trial runs with your parents to become familiar with the trains/area--let them see your maturity on how you handle yourself with crowds and restaurants etc.
Your time will come and part of growing up is cutting that parental string--the child always wants the scissors first.
Be a child a little longer--the reward will be that much sweeter.