i think that is wholey good advice!! i know its not easy from experience, but ive known for much longer, and i mean 11 years, only recently though told anyone, and its scary!! but, my friends are so suportive and like me regardless!!
i think you should give it time and see if any, which you tend to prefer!!
it may take time but i think you will figure it out!
as for the girl, send her a friendly message, bu i have a question, is she likely to feel the same, i mean, does she like girls in that way. if not, be very careful, getting involved with straight girls is generaly a bad idea, they tend to break your heart!! just a warnig, but there is no harm in trying to begin with!!
all the best, Sally xx