Going tandem skydiving for the first time?

On my 18th birthday in December I'm going tandem skydiving, I've been wanting to do this for years and am really eager and excited. But what are the odds of actually dieing? Like slipping out of the harness, or all the parachutes malfunctioning? Compared to other deaths such as car accidents or lightning strikes lol. And will I be able to breathe good on the free fall? One more question, what should I expect from "parachute opening shock?" Thanks :)