If you don't want to be in the friend zone, then you have to frame the relationship romantically. It looks to me like you are jumping right to being friends before you have established a romantic relationship. My advice would be to invite her to do something with you where you can push to see if she's interested in being more than friends. Holding hands, kissing (even on the cheek), or holding her back can be easy ways to escalate the relationship forward. If she is into you she probably is waiting for you to do this anyway, and if not then she's not interested. Either way you need to find out quickly, otherwise you are wasting your time with her.
If you don't want to be nervous, then prepare as you would for anything. Plan ahead open ended conversation topics and places you can go. Always have multiple places that you can go based on how things progress. Something else that helps is to frame your mindset such that it doesn't matter if it goes well or not (at least initially). There are millions of women for you to choose from, so loosing this one is just a learning experience for the next one.
HTH...