First of all you need to know how much money you earn, for some people this is easy you look at your Wθ form and there it is, but for seasonal workers, small business people, it gets a little more complicated than that. If you receive income from a lot of different sources for a realistic value of what you actually earn itemize them, put them down on paper. Include all income, now is not the time to be hide money from the IRS you are just fooling yourself, you need to have factual figures here of your true income otherwise you will actually think you're in good financial shape because you know you got this extra income somewhere, but that's not always true.
A wedding can be a very expensive. For this reason, it's important that you make a budget before you start planning your wedding. If you know how much you have to spend and should be spending on each part of your wedding, you shouldn't have any trouble pulling off a wedding on a budget whatsoever.