You are picturing the scene already: family gathered on the grass, bakery trays laid out, and nobody stuck inside flipping pancakes. A catered backyard baby shower brunch takes the pressure off the day itself, but it brings a few bills due all at once.
Timing is everything when you are pulling this together. Ordering bakery trays and catering packages four weeks out gives you the lock on your date and keeps you from paying rush fees on top of the about $1200 typical US cost.
That 0% window is a deadline, not free money. If you still have a balance left on the Citi Simplicity® Credit Card when the 18 months are up, regular interest kicks in on what you bought.