Most Helpful Girl
Join a club, get into an interest group. There you'll develop other passions and meet girls and you can discuss your common interest (whatever new skill you've taken up). It'll make you a more interesting person to others as well.
Most Helpful Guy
I'm sort of in the same hole as you. I'm attractive and smart, but I rarely approach girls. My situation is different in the aspect that I have had a long term relationship (that I just got out of) and I choose to rarely approach girls because, just like you, I am disgusted by girls that party all the time and sleep around. I'm also picky. I won't waste my time if she's missing something. That doesn't mean that I don't make exceptions or talk to any girls at all, but anyways you have to force yourself to be more social. Try to become friends with some girls that you are not attracted to and vice versa. This will help you get familiar. My friend group is majorly lacking girls, but we have a few, and I'm friends with many others, and trust me it helps. Once you get used to talking to them you begin to figure out that that talking to a girl really isn't that different from talking to a guy. Obviously you don't want to be immature and rude like some of us are with our guys friends, but treat her as an equal and not some goddess, and she will notice and appreciate it. Just go with the flow of things. If she wants the friendship to be something more then you'll usually notice. Some girls take it very slow while others go out after knowing the guy for a few days. Don't forget how you feel though! Think about if you want to take it to the next level or not. And with your question about taking it to the next level, all I can say is that there is no specific way to do it. It's always different depending on the person, and you just kind of merge into it. Hope this helps!