As an MC you have one of the most important parts of the day, so plan, practice and prepare!!
But don't stress. Follow the tips below and you'll be well on your way of being in the top 10% of MC's I've worked with. Don't be like the guy who drank tequilas to calm his nerves, only for me to have to take over from him before dinner as he needed a nap (Let's just leave it there ).
Having a order of events is crucial, here's an general
Order of Events which will work for most weddings, tweak as needed.