Relax and enjoy it. Assuming of course that she's the one for you, you will have the biggest smile on your face all day. Don't listen to everyone else above; it's kids that stop you riding, not wives!
Other tips?
Don't write your speech the morning of the wedding like I did. Spend the time with friends and family instead
Have a "quiet" stag do the night before. My wife had a meal out with mums and friends. I sat at home on me tod 🙁
If you've got friends/family taking pics/vids make sure you let them know what you want the pics and vids of. Our photographer was a semi-pro family friend on my wife's side. The pics were great, but most of them were her family and friends and not mine.
Relax and enjoy