Hello, I guess that the most important thing is to have the good husband-to-be aha 😉
Seriously, you have to set the tone of your event.This is the time to decide if you're having a formal wedding, a casual affair, or a theme wedding. It's also the time to decide if you're having a religious or secular ceremony.
Then you have to set the budget, start off by finding a wedding budget worksheet. Look at your finances and figure out how much you already have in savings, and how much you can save each month. Talk to each of your parents and ask them if they'd like to contribute to your wedding, and either how much they'd like to give you, or what specific things they'd like to pay for.
When that's done, you can start looking for venues for ceremony and reception. Consider hiring a wedding planner or consultant. Especially if you are a busy person, or just feel a little lost, a professional can be invaluable in putting together your ideal day, and can often save you money.