Your Player ID Number is the identifier for your account. This is also the number you give to your friends so that they can add you.
You can get your Player ID Number by:
1. Looking in the upper right section of the starting screen
1. Tap Home then tap Menu
2. Tap Player Info
3. It is the number after ID to the right
It's important to remember or store your Player ID Number in case you need it for something related to your account.