Woah woah first off my friend don't ever get your self in that situation. It's very hard to get out of and yes you can get out of it I've done it before for the sole purpose of seeing if it was possible. Keep in mind that if there's a spark of attraction on both ends your still good but if there's nothing screw it move on. Stop worrying about is she going to put me only as a friend when your on a date with her it will only make you nervous and then guess what your a friend. What you need to do is to go in there and act like you've known her for a long time, joke around with her make her laugh, don't be afraid to make fun her playfully , hold her hand, tickle her, and don't let her mess with your mind and if she does don't let her know about it. Don't get frustrated with her or anything you gotta keep the ball in your court not hers, do not lose control of the situation. Here's a way of knowing if she's interested in you go on a date, have fun with her and try and kiss her. If you succeed or say you don't get the kiss that's ok. If she likes you she will contact you with the next day usually, or if she doesn't then don't talk to her her for about 2 days and if she likes you she will contact you.
Depends on the girl. But most girls, when they meet a guy keep him in the acquaintance zone for a while until they figure out if he's worth the bother of being their friend. If he is he finds himself in the friends zone, which is a really comfortable place, and in which there is no shifting unless both sides start to feel some kind of an attraction going on. If the attraction kicks in immediately after the first encounter it means you have definite boyfriend potential and the 'friend zone' is the farthest thing from her mind. If she sees you with another girl or she hears you have a girlfriend that is like an alarm telling her to place you into the friend zone, and not ever think of you in a romantic way again.
The most important thing you have to remember here is that there is a great possibility of shifting from friend zone to dating zone and vice-versa. BUT if that shift happens once (no matter in which direction it went) you can never go back!