Way to go, Marie!
I think you're doing just fine. You better believe I'm taking notes for when it's my turn to walk into a social situation like that.
If you really feel that you need some pre-party introduction, then your idea of calling for directions is a good and very plausible one. If nothing else, you will feel a bit more like you "know" someone there, and not like you're on another planet.
As far as how to meet strangers in a group, here's my advice from quite a few years (!!!) walking into "cold" cocktail parties for work and church, charity galas, college alumni meetings etc:
Smile!
No kidding, it really is that simple. A big, sincere, toothy, happy, outgoing smile will open every door every time. You will appear to others that you are 100% calm, cool, collected and above all: happy with yourself and comfortable in your own skin. Just like the alum prez said just introduce yourself. Stick your hand out to shake and start talking. It works--not only on others but it will make you more at ease too!
Adrienne
(If you have to do this all night (4+ hours), don't forget a touch of Vaseline on your teeth. Anyone who wants the details of that little gem, PM me.)