There are four types of Osushi. Nigiri is the most popular osushi in Japan. Gunkan and Makizushi are wrapped by Nori. These three are good to eat with Shoyu (soy source). Chirashi is rice for the special day like Hinamatsuri and New year.
Most Japanese eat Osushi with chopsticks. But if you are not used to using it, try to eat carefully. It might fall from your chopsticks!
You can eat by hands in front of Itamae who is serving at Osushi restuarant. Your hands are going to messy? Don't worry! You can wipe off with Oshibori.