3 day potty training method

I start potty training my 22 month old son tomorrow using the three day method. I've read the book we've got the potties, the underwear, and I think we're ready, but I'm so nervous that it's just not gonna work. Has anyone used this method or another method that has any tips to share anything to calm my nerves and help? I feel like I'm over thinking this, but I'm scared I'm gonna mess it up.