"(Watashi no) namae wa ..... desu," or, "(Watashi wa)... desu. Do not use "o-namae" here; only use that when refering to someone else's name. The "o" is an honorific prefix. In this case, using it with "namae," for your own name probably would make you sound snobbish. "Watashi no"/"Watashi wa" can be left out sometimes because the fact that it is your name is obvious, especially if someone asked you first.
Note: the "wa" particle is written with the "ha" hiragana but in this context as the topic marker, it is pronounced "wa."