Sad to say, but you're not going to find a situation of saving or rescuing a girl like what is essentially a fairytale right out of Disney. Not unless you want to try a relationship with someone incredibly damaged and needy. ...And then I'd think more of exploitation than any actual romance. :/
You're better off talking to interesting girls that are in places you frequent and enjoy being around. See if you click as friends first. And if she really likes you, she might start viewing you as a light in her life that was much appreciated and will appreciate what you gave to her all the more; which is more what you should be after vs someone completely dependent on you.
That notion is romanticized; do you know how much work it really is dealing with someone codependent on you? You wouldn't want to stay with them for long, which will only damage them further. Fairytales make it look easy, but that ain't reality.