Like others have said join a club or something or get a hobby which involves socialising.... and when talking to people the most important thing is to relax and be yourself !!!

As for talking to the "ear phone" people, avoid these people, they wear ear phones for a reason, they DON'T want to talk to you.... thats why they dont smile back at you !

Also you mentioned talking to "young" people, how young are we talking ? early 20's ? if so theres your problem, they see you as an old fart and cant be bothered talking to someone in their early thirties.. if i was back in my early twenties and some strange guy in his thirties walked up to me and started talking to me for no reason i would be like "WTF why the hell is this creepy gimp talking to me !!!", and if your talking to girls in their early twenties your wasting your time unless you are an extremely good looking guy or ugly and have a lot of money.....

IF your main agenda for talking to people is just for potential dating just join a dating website, stick your pic on it all your likes dislikes and such and say something like your a shy but nice guy who is genuinely looking for friendship or more !  Im sure someone will bite (they most likely wont be a twentysomething hot chick, more than likely a woman in her thirties)