First off start with cooked sushi first. Yes not all sushi is served raw. Eel (unagi and anago) is always served cooked and so are California rolls. I found this great article that is about beginner sushi eaters. http://www.sushifaq.com/sushiforbeginners.htm
Nothing to fear about sushi in terms of taste. Somethings you might like others you won't. But the most important thing to remember is, choose a good place. I never eat raw fish from a stand or the mall for that matter.
Shrimp tempura and crunch rolls are good to start with. If you like seafood than more than likely you will like it raw, too. For raw, try salmon sushi, yellowtail, and tuna. This first two are more flavorful because they are fattier fish. It will come down to what you prefer. Don't start off with "all you can eat" because unless it was highly recommended, the fish is usually not the best and most flavorful. Ask for recommendations in your town.