Hi
Congratulations on getting engaged!
With the wedding in march you have plenty of time to lose a lot of weight and getting healthy
Take your time to look around the site, as there is lots of help and advice to be had here
While you are doing this I would suggest some things you could do immediatly which would help you get off to a good start
You're a big guy so I'd have thought about 2200 calories a day should be a good amount for you to start losing weight. It may be hard at first but you'll soon find foods, such as carrots, oatmeal, etc, which are very few in calories but which fill you up nicely.
Some things are just terrible for diets, so try to take them out of your food intake completely. These include alcohol, sweets, fast food, mayonaise, cheese. I know they are lovely, but it has to be done.
Try and walk for an hour a day. You can split this up into 2 lots of half an hour for the first week.
You've got plenty of time to lose the weight, but a diet has to be well planned with the right info.
all the best