If you need to find your order number, here's what you can do: check your email inbox for any order confirmation emails you may have received, look at your physical receipt or packing slip for the order number, or log in to your account on the website where you placed the order and check your order history page.
Web orders will have a 4- or 5- digit number that will look like this: #1001. Enter this entire number. Phone and in-store orders will likely have a longer number like this: 220000634304. If you have a phone order that only has the last 6 digits, try entering "220000" in front of it to track your order or start a return.