People have been asking here about charging to their Magic Band, so here is a reminder for them -
If you are staying at a Disney hotel, your hotel stay should be in your
MDE account. Normally it goes in there automatically when you make the hotel resie. If it doesn't (as in some DVC stays), you enter the confirmation number into your MDE account yourself. Most people do this before their trip because having your hotel stay in your MDE account is what allows you to make fastpasses at 60 days out.
The first time you do online check in for a Disney hotel, you have to create a 4-digit PIN.
The next time you do online check in, you do not have to create a new PIN if you remember the old one.
Once you are at Disney World, you can use your Magic Band to charge purchases
to your hotel room. When you are at a cash register, you tap your Magic Band (on the same box where you would swipe or enter your credit card if you were paying that way). After you tap your Magic Band, you have to enter your PIN to complete the purchase.
If you are not staying at a Disney hotel, you cannot use your Magic Band to make purchases. This is because you do not charge to the Magic Band itself; the Magic Band is merely a tool for charging to your hotel room.
If you want to use your Magic Band to charge purchases to your hotel room, but you never did online check in -- you never created a PIN, but you can create one when you check in at your hotel.
If you want to use your Magic Band to charge purchases to your hotel room but you forgot your PIN -- you should be able to create a new PIN at your hotel's registration desk.