There are as many yoga styles, classes and teachers as there are yoga poses and breathing techniques. To start, rent videos from Netflix or your local video store to get a flavor of what a yoga class will be like and get a sense of some of the different yoga styles. Additionally, start sampling your local studios. Take different classes there as well as try different teachers. Ask questions after each class to get a better understanding of the style of class you just took.
As you explore yoga, be open to experimenting. As always, trust your instincts. Your body and mind will tell you what style is healthy for you.