Don't look at the habits of your more experienced friends as any sort of guide. Learn what you can order, and from whom If the sushi bar is but part of a larger, full-service restaurant, be aware that only sushi, sashimi, soups, drinks and some snacks are served there. If you're having a sushi-only experience, consider sitting up at the sushi bar rather than at a table or booth. That way you can point at what looks intriguing, or even ask the chef to improvise. The best bet is to start simply and work up from there as your palate becomes more educated to the shadings of sushi flavors.
Greens usually consist of cucumber strips and a wonderful, seasoned white vinegar.
Miso soup is a warm broth with chunks of tofu, and often with strips of vegetables. Sip this with both hands on the bowl, letting yourself be wild without a spoon. Choose a basic roll. There are several basic rolls that are the standard for any sushi menu. They are usually all small and served in quantities of six, though the servings may vary from place to place.