Weddingbee boards

Well, now that I am meeting many relatives and soon to be a member of the family, I am being invited to many events.  In fact 3 Bar mitzvahs in the last 5 months!  I've one more to go to and I need help.  HOW CAN MY FI BE SO LACKING HERE?  I am to attend an Orthodox Bar Mitzvah Ceremony in NY, (men and women separate etc) I am conservative but live in an Orthodox community of Hancock Park in Los Angeles.  What I see here does not jive with what might be acceptable in NY.  What am I required to do?  Must I wear high neck, long sleeves and cover my ankles???  I rarely see long skirts in my neighborhood.  Also must I wear a hat or wig?  I just dont want to do the wrong thing.  I dont mind buying whatever I should have. ANY HELP WOULD BE APPRECIATED!  

Thanks