Welcome Aboard, Sarah!
Please don't stress out about what night you will be wearing which outfit. At this point, it is too early for even Disney Cruise Line to determine which night each of these will be happening. As long as you have all of your outfits packed, you will be fine.
For sure, your first night onboard will be cruise casual. This simply means that swimwear and tank tops are not allowed in the main dining rooms. You will also have a dining room schedule printed on your Key To The World card. Your dining room team can tell you which nights are coming up.
When sailing on a 7-Night sailing on any Disney Cruise Line ship, you can expect one optional formal night and one optional semi-formal night, where your fellow passengers will be dressed in everything from ball gowns and tuxedos (my dress of choice) to sundresses and polos with khakis. The choice is completely yours, which is why it is "optional". Whatever you are comfortable wearing, it is your choice.
Somewhere in the middle of your cruise, you will experience Pirate Night. At this time, passengers young and old will be dressed in their pirate-y best (or worst!). This is my favorite night on my Disney Cruise Line vacations. We go all out and wear full pirate outfits, my husband even has a parrot for his shoulder!
So, please, relax and get ready for one of the best vacations you have ever experienced! Each night, a Daily Navigator will be delivered to your room. This will have a schedule of the following days events, along with what the dress code for dinner is. You will most likely spend the majority of your days in your swimsuit, leaving the pool with just enough time to shower and change for dinner.
I hope you have an amazing time on the Disney Magic out of New York next year!
Happy Cruising, Tracy V.