The first thing I can recommend is to buy the book "The Wedding MC"
https://www.amazon.ca/Wedding-MC-Com...3450253&sr=8-1
It's got a ton of good info and ideas. When I MC'd my friends wedding I sat down with them after reading that and there were all sorts of things that they hadn't even thought of, and I wouldn't have thought to ask if I hadn't read that book.
A few tips:
1) Drink less than you think you can/should
2) It's not your job to put on a show, it's your job to keep the show going, elaborate bits never go as well as you think they will, basically do, and say less than you think you can/should. Everyone has limited time to enjoy the wedding, don't fill it up with too many jokes and bits, you can be funny without putting on a show.
3) I'm not sure if this is in the book, but no matter what the bride and groom say, DO NOT DO/ALLOW an open mic, no one has ever left a wedding thinking "Wow, that 20 minutes of inside jokes and awkward stories were great, especially when drunk uncle made all those totally inappropriate jokes.
Take my advice for what it is worth, but I really can't stress enough, buy/read that book, it's a great starting point and will give you a lot to think about.