Because I've never been on a date in my life.
Dates are really not all they're cracked up to be in the movies. If your sole objective is to go on a date because you haven't, there's really no point. If your idea is to meet a person/people that you can establish a relationship with, allow me to point you to Lavalife, Plenty of Fish, or another of the plethora of online services for meeting people.
More importantly, if you want to get to know a girl better, ask her to do things with you. Doesn't have to be a dinner date, doesn't have to be a coffee date, it can simply be going for a walk. But you have to ASK. Never asking while waiting for some mythical sign, and you'll be waiting a long time. The worst they can say is "no," and then you have your answer and can direct your energies elsewhere.
Seriously, what the **** is with socially-awkward teenage boys and this fear of rejection... there are more women on the planet than men, the odds ARE in your favour. Rejection is best thought of as practice and learning experiences on your way to meeting the right person/people. Don't fear it.
EDIT: One other thing - people can sense desperation, and its a huge turn-off. If you are desperate to go on a date or get into a relationship, it's going to hurt your chances of it. The right person comes along when you least expect it (in my case, I met my wife after having sworn off relationships in general due to a run of bad ones, and we met while volunteering at a service in University - and SHE was the one who asked ME out).